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2683a02a | 1 | ## $Cambridge: exim/doc/doc-src/FAQ.src,v 1.2 2004/10/12 09:54:44 ph10 Exp $ |
495ae4b0 PH |
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36 | ## detected by the scripts. | |
37 | ## | |
38 | ## | |
39 | THE EXIM FAQ | |
40 | ------------ | |
41 | ||
42 | This is the FAQ for the Exim Mail Transfer Agent. Many thanks to the many | |
43 | people who provided the original information. This file would be amazingly | |
44 | cluttered if I tried to list them all. Suggestions for corrections, | |
45 | improvements, and additions are always welcome. | |
46 | ||
47 | This version of the FAQ applies to Exim 4.00 and later releases. It has been | |
48 | extensively revised, and material that was relevant only to earlier releases | |
49 | has been removed. As this caused some whole sections to disappear, I've taken | |
50 | the opportunity to re-arrange the sections and renumber everything except the | |
51 | configuration samples. | |
52 | ||
53 | References of the form Cnnn, Fnnn, Lnnn, and Snnn are to the sample | |
54 | configuration, filter, \^^local_scan()^^\, and ``useful script'' files. These | |
55 | are hyperlinked from the HTML version of this FAQ. They can also be found in | |
56 | the separately distributed directory called \(config.samples)\. The primary | |
57 | location is | |
58 | ||
59 | \?ftp://ftp.csx.cam.ac.uk/pub/software/email/exim/exim4/config.samples.tar.gz?\ | |
60 | \?ftp://ftp.csx.cam.ac.uk/pub/software/email/exim/exim4/config.samples.tar.bz2?\ | |
61 | ||
62 | There are brief descriptions of these files at the end of this document. | |
63 | ||
64 | Philip Hazel | |
2683a02a | 65 | Last update: 12-October-2004 |
495ae4b0 PH |
66 | |
67 | ||
68 | The FAQ is divided into the following sections: | |
69 | ||
70 | 0. General Debugging | |
71 | 1. Building and Installing | |
72 | 2. Routing in general | |
73 | 3. Routing to remote hosts | |
74 | 4. Routing for local delivery | |
75 | 5. Filtering | |
76 | 6. Delivery | |
77 | 7. Policy controls | |
78 | 8. Rewriting addresses | |
79 | 9. Headers | |
80 | 10. Performance | |
81 | 11. Majordomo | |
82 | 12. Fetchmail | |
83 | 13. Perl | |
84 | 14. Dial-up and ISDN | |
85 | 15. UUCP | |
86 | 16. Modifying message bodies | |
87 | 17. Encryption (TLS/SSL) | |
88 | 20. Millennium | |
89 | 50. Miscellaneous | |
90 | 91. Mac OS X | |
91 | 92. FreeBSD | |
92 | 93. HP-UX | |
93 | 94. BSDI | |
94 | 95. IRIX | |
95 | 96. Linux | |
96 | 97. Sun sytems | |
97 | 98. Configuration cookbook | |
98 | 99. List of sample configurations | |
99 | ||
100 | ||
101 | ||
102 | 0. GENERAL DEBUGGING | |
103 | ||
104 | Q0001: Exim is crashing. What is wrong? | |
105 | ||
106 | A0001: Exim should never crash. The author is always keen to know about | |
107 | crashes, so that they can be diagnosed and fixed. However, before you | |
108 | start sending me email, please check that you are running the latest | |
109 | release of Exim, in case the problem has already been fixed. The | |
110 | techniques described below can also be useful in trying to pin down | |
111 | exactly which circumstances caused the crash and what Exim was trying to | |
112 | do at the time. If the crash is reproducable (by a particular message, | |
113 | say) keep a copy of that message. | |
114 | ||
115 | ||
116 | Q0002: Exim is not working. What is wrong? How can I check what it is doing? | |
117 | ||
118 | A0002: Exactly how is it not working? Check the more specific questions in the | |
119 | other sections of this FAQ. Some general techniques for debugging are: | |
120 | ||
121 | (1) Look for information in Exim's log files. These are in the \(log)\ | |
122 | directory in Exim's spool directory, unless you have configured a | |
123 | different path for them. Serious operational problems are reported | |
124 | in paniclog. | |
125 | ||
126 | (2) If the problem involves the delivery of one or more messages, try | |
127 | forcing a delivery with the \-M-\ option and also set the \-d-\ | |
128 | option, to cause Exim to output debugging information. For example: | |
129 | ||
130 | ==> exim -d -M 0z6CXU-0005RR-00 | |
131 | ||
132 | The output is written to the standard error stream. You need to have | |
133 | admin privileges to use \-M-\ and \-d-\. | |
134 | ||
135 | (3) If the problem involves incoming SMTP mail, try using the \-bh-\ | |
136 | option to simulate an incoming connection from a specific host, | |
137 | for example: | |
138 | ||
139 | ==> exim -bh 10.9.8.7 | |
140 | ||
141 | This goes through the motions of an SMTP session, without actually | |
142 | accepting a message. Information about various policy checks is | |
143 | output. You will need to know how to pretend to be an SMTP client. | |
144 | ||
145 | (4) If the problem involves lack of recognition or incorrect handling | |
146 | of local addresses, try using the \-bt-\ option with debugging turned | |
147 | on, to see how Exim is handling the address. For example, | |
148 | ||
149 | ==> exim -d -bt z6abc | |
150 | ||
151 | shows you how it would handle the local part \"z6abc"\. | |
152 | ||
153 | ||
154 | Q0003: What does the error \*Child process of address_pipe transport returned | |
155 | 69 from command xxx*\ mean? | |
156 | ||
157 | A0003: It means that when a transport called \%address_pipe%\ was run to pass an | |
158 | email message by means of a pipe to another process running the command | |
159 | xxx, the return code from that command was 69, which indicates some kind | |
160 | of error (the success return code is 0). | |
161 | ||
162 | The most common meaning of exit code 69 is ``unavailable'', and this often | |
163 | means that when Exim tried to run the command \(xxx)\, it failed. One | |
164 | cause of this might be incorrect permissions on the file containing the | |
165 | command. See also Q0026. | |
166 | ||
167 | ||
168 | Q0004: My virtual domain setup isn't working. How can I debug it? | |
169 | ||
170 | A0004: You can use an exim command with \-d-\ to get it to show you how it is | |
171 | processing addresses. You don't actually need to send a message; use the | |
172 | \-bt-\ option like this: | |
173 | ||
174 | ==> exim -d -bt localpart@virtualhost | |
175 | ||
176 | This will show you which routers it is using. If the problem appears | |
177 | to be with the expansion of an option setting, you can use the | |
178 | \debug_print\ option on a router to get Exim to output the expanded | |
179 | string values as it goes along. | |
180 | ||
181 | ||
182 | Q0005: Why is Exim not rejecting incoming messages addressed to non-existent | |
183 | users at SMTP time? | |
184 | ||
185 | A0005: This is controlled by the ACL that is run for each incoming RCPT | |
186 | command. It is defined by the \acl_smtp_rcpt\ option. You can check this | |
187 | part of your configuration by using the \-bh-\ option to run a simulated | |
188 | SMTP session, during which Exim will tell you what things it is | |
189 | checking. | |
190 | ||
191 | ||
192 | Q0006: I've put an entry for \"*.my.domain"\ in a DBM lookup file, but it isn't | |
193 | getting recognized. | |
194 | ||
195 | A0006: You need to request ``partial matching'' by setting the search type to | |
196 | \partial-dbm\ in order for this to work. | |
197 | ||
198 | ||
199 | Q0007: I've put the entry \"*@domain.com"\ in a lookup database, but it isn't | |
200 | working. The expansion I'm using is: | |
201 | ||
202 | ==> ${lookup{${lc:$sender_address}}dbm{/the/file} ... | |
203 | ||
204 | A0007: As no sender address will ever be //*@domain.com// this will indeed have | |
205 | no effect as it stands. You need to tell Exim that you want it to look | |
206 | for defaults after the normal lookup has failed. In this case, change the | |
207 | search type from \"dbm"\ to \"dbm*@"\. See the section on \*Default values in | |
208 | single-key lookups*\ in the chapter entitled \*File and database | |
209 | lookups*\ in the Exim manual. | |
210 | ||
211 | ||
212 | Q0008: If I run \"./exim -d -bt user@domain"\ all seems well, but when I send | |
213 | a message from my User Agent, it does not arrive at its destination. | |
214 | ||
215 | A0008: Try sending a message directly to Exim by typing this: | |
216 | ||
217 | ==> exim -v user@domain | |
218 | <some message, could be empty> | |
219 | . | |
220 | ||
221 | If the message gets delivered to a remote host, but never arrives at its | |
222 | final destination, then the problem is at the remote host. If, however, | |
223 | the message gets through correctly, then the problem may be between your | |
224 | User Agent and Exim. Try setting Exim's \log_selector\ option to include | |
225 | \"+arguments"\, to see with which arguments the UA is calling Exim. | |
226 | ||
227 | ||
228 | Q0009: What does \*no immediate delivery: too many messages received in one SMTP | |
229 | connection*\ mean? | |
230 | ||
231 | A0009: An SMTP client may send any number of messages down a single SMTP | |
232 | connection to a server. Initially, an Exim server starts up a delivery | |
233 | process as soon as a message is received. However, in order not to start | |
234 | up too many processes when lots of messages are arriving (typically | |
235 | after a period of downtime), it stops doing immediate delivery after a | |
236 | certain number of messages have arrived down the same connection. The | |
237 | threshold is set by \smtp_accept_queue_per_connection\, and the default | |
238 | value is 10. On large systems, the value should be increased. If you are | |
239 | running a dial-in host and expecting to get all your mail down a single | |
240 | SMTP connection, then you can disable the limit altogether by setting | |
241 | the value to zero. | |
242 | ||
243 | ||
244 | Q0010: Exim puts \*for \[address]\*\ in the ::Received:: headers of some, but not all, | |
245 | messages. Is this a bug? | |
246 | ||
247 | A0010: No. It is deliberate. Exim inserts a ``for'' phrase only if the incoming | |
248 | message has precisely one recipient. If there is more than one | |
249 | recipient, nothing is inserted. The reason for this is that not all | |
250 | recipients appear in the ::To:: or ::Cc:: headers, and it is considered a | |
251 | breach of privacy to expose such recipients to the others. A common | |
252 | case is when a message has come from a mailing list. | |
253 | ||
254 | ||
255 | Q0011: Instead of \^exim_dbmbuild^\, I'm using a homegrown program to build DBM | |
256 | (or cdb) files, but Exim doesn't seem to be able to use them. | |
257 | ||
258 | A0011: Exim expects there to be a binary zero value on the end of each key used | |
259 | in a DBM file if you use the \"dbm"\ lookup type, but not for the \"dbmnz"\ | |
260 | lookup type or for the keys of a cdb file. Check that you haven't | |
261 | slipped up in this regard. | |
262 | ||
263 | ||
264 | Q0012: Exim is unable to route to any remote domains. It doesn't seen to be | |
265 | able to access the DNS. | |
266 | ||
267 | A0012: Try running \"exim -d+resolver -bt \[remote address]\"\. The \-d-\ | |
268 | options turns on debugging output, and the addition of \"+resolver"\ | |
269 | will make it show the resolver queries it is building and the results of | |
270 | its DNS queries. If it appears unable to contact any name servers, check | |
271 | the contents and permissions of \(/etc/resolv.conf)\. | |
272 | ||
273 | ||
274 | Q0013: What does the error message \*transport system_aliases: cannot find | |
275 | transport driver "redirect" in line 92*\ mean? | |
276 | ||
277 | A0013: \%redirect%\ is a router, not a transport. You have put a configuration | |
278 | for a router into the transports section of the configuration file. | |
279 | ||
280 | ||
281 | Q0014: Exim is timing out after receiving and responding to the DATA command | |
282 | from one particular host, and yet the client host also claims to be | |
283 | timing out. This seems to affect only certain messages. | |
284 | ||
285 | A0014: This kind of problem can have many different causes. | |
286 | ||
287 | (1) This problem has been seen with a network that was dropping all | |
288 | packets over a certain size, which mean that the first part of the SMTP | |
289 | transaction worked, but when the body of a large message started | |
290 | flowing, the main data bits never got through the network. See also | |
291 | Q0017. | |
292 | ||
293 | (2) This can also happen if a host has a broken TCP stack and won't | |
294 | reassemble fragmented datagrams. | |
295 | ||
296 | (3) A very few ISDN lines have been seen which failed when certain data | |
297 | patterns were sent through them, and replacing the routers at both end | |
298 | of the link did not fix things. One of them was triggered by more than 4 | |
299 | X's in a row in the data. | |
300 | ||
301 | ||
302 | Q0015: What does the message \*Socket bind() to port 25 for address (any) | |
303 | failed: address already in use*\ mean? | |
304 | ||
305 | A0015: You are trying to run an Exim daemon when there is one already running - | |
306 | or maybe some other MTA is running, or perhaps you have an SMTP line in | |
307 | \(/etc/inetd.conf)\ which is causing \(inetd)\ to listen on port 25. | |
308 | ||
309 | ||
310 | Q0016: I've set \"verify = header_syntax"\ in my ACL, but this causes Exim to | |
311 | complain about header lines like \"To: Work: Jim <jims@email>, | |
312 | Home: Bob <bobs@email>"\ which look all right to me. Is this a bug? | |
313 | ||
314 | A0016: No. Header lines such as ::From::, ::To::, etc., which contain addresses, are | |
315 | structured, and have to be in a specific format which is defined in RFC | |
316 | 2822. Unquoted colons are not allowed in the ``phrase'' part of an email | |
317 | address (they are OK in other headers such as ::Subject::). The correct | |
318 | form for that header is | |
319 | ||
320 | ==> To: "Work: Jim" <jims@email>, "Home: Bob" <bobs@email> | |
321 | ||
322 | You will sometimes see unquoted colons in ::To:: and ::Cc:: headers, but only | |
323 | in connection with name lists (called ``groups''), for example: | |
324 | ||
325 | ==> To: My friends: X <x@y.x>, Y <y@w.z>;, | |
326 | My enemies: A <a@b.c>, B <b@c.d>; | |
327 | ||
328 | Each list must be terminated by a semicolon, as shown. | |
329 | ||
330 | ||
331 | Q0017: Whenever Exim tries to deliver a specific message to a particular | |
332 | server, it fails, giving the error \*Remote end closed connection after | |
333 | data*\ or \*Broken pipe*\ or a timeout. What's going on? | |
334 | ||
335 | A0017: \*Broken pipe*\ is the error you get on some OS when the remote host just | |
336 | drops the connection. The alternative is \*connection reset by peer*\. | |
337 | There are many potential causes. Here are some of them (see also Q0068): | |
338 | ||
339 | (1) There are some firewalls that fall over on binary zero characters | |
340 | in email. Have a look, e.g. with \"hexdump -c mymail | tail"\ to see if | |
341 | your mail contains any binary zero characters. | |
342 | ||
343 | (2) There are broken SMTP servers around that just drop the connection | |
344 | after the data has been sent if they don't like the message for some | |
345 | reason (e.g. it is too big) instead of sending a 5xx error code. Have | |
346 | you tried sending a small message to the same address? | |
347 | ||
348 | It has been reported that some releases of Novell servers running NIMS | |
349 | are unable to handle lines longer than 1024 characters, and just close | |
350 | the connection. This is an example of this behaviour. | |
351 | ||
352 | (3) If the problem occurs right at the start of the mail, then it could | |
353 | be a network problem with mishandling of large packets. Many emails are | |
354 | small and thus appear to propagate correctly, but big emails will | |
355 | generate big IP datagrams. | |
356 | ||
357 | There have been problems when something in the middle of the network | |
358 | mishandles large packets due to IP tunnelling. In a tunnelled link, your | |
359 | IP datagrams gets wrapped in a larger datagram and sent over a network. | |
360 | This is how virtual private networks (VPNs), and some ISP transit | |
361 | circuits work. Since the datagrams going over the tunnel require a | |
362 | larger packet size, the tunnel needs a bigger maximum transfer unit | |
363 | (MTU) in the network handling the tunnelled packets. However, MTUs | |
364 | are often fixed, so the tunnel will try to fragment the packets. | |
365 | ||
366 | If the systems outside the tunnel are using path MTU discovery, (most | |
367 | Sun Sparc Solaris machines do by default), and set the DF (don't | |
368 | fragment) bit because they don't send packets larger than their \(local)\ | |
369 | MTU, then ICMP control messages will be sent by the routers at the | |
370 | ends of the tunnel to tell them to reduce their MTU, since the tunnel | |
371 | can't fragment the data, and has to throw it away. If this mechanism | |
372 | stops working, e.g. a firewall blocks ICMP, then your host never | |
373 | knows it has hit the maximum path MTU, but it has received no ACK on | |
374 | the packet either, so it continues to resend the same packet and the | |
375 | connection stalls, eventually timing out. | |
376 | ||
377 | You can test the link using pings of large packets and see what works: | |
378 | ||
379 | ==> ping -s host 2048 | |
380 | ||
381 | Try reducing the MTU on the sending host: | |
382 | ||
383 | ==> ifconfig le0 mtu 1300 | |
384 | ||
385 | Alternatively, you can reduce the size of the buffer Exim uses for SMTP | |
386 | output by putting something like | |
387 | ||
388 | ==> DELIVER_OUT_BUFFER_SIZE=512 | |
389 | ||
390 | in your \(Local/Makefile)\ and rebuilding Exim (the default is 8192). | |
391 | While this should not in principle have any effect on the size of | |
392 | packets sent, in practice it does seem to have an effect on some OS. | |
393 | ||
394 | You can also try disabling path MTU discovery on the sending host. On | |
395 | Linux, try: | |
396 | ||
397 | ==> echo 1 >/proc/sys/net/ipv4/ip_no_pmtu_disc | |
398 | ||
399 | For a general discussion and information about other operating systems, see | |
400 | \?http://www.netheaven.com/pmtu.html?\. If disabling path MTU discovery | |
401 | fixes the problem, try to find the broken or misconfigured | |
402 | router/firewall that swallows the ICMP-unreachable packets. Increasing | |
403 | timeouts on the receiving host will not work around the problem. | |
404 | ||
405 | ||
406 | Q0018: Why do messages not get delivered down the same connection when I do | |
407 | something like: \"exim -v -R @aol.com"\? For other domains, I do this and | |
408 | I see the appropriate \*waiting for passed connections to get used*\ | |
409 | messages. | |
410 | ||
411 | A0018: Recall that Exim does not keep separate queues for each domain, but | |
412 | operates in a distributed fashion. Messages get into its `waiting for | |
413 | host x' hints database only when a delivery has been tried, and has had | |
414 | a temporary error. Here are some possibilities: | |
415 | ||
416 | (1) The messages to \(aol.com)\ got put in your queue, but no previous | |
417 | delivery attempt occured before you did the \-R-\. This might have been | |
418 | because of your settings of \queue_only_load\, \smtp_accept_queue\, or any | |
419 | other option that caused no immediate delivery attempt on arrival. If | |
420 | this is the case, you can try using \-qqR-\ instead of \-R-\. | |
421 | ||
422 | (2) You have set \connection_max_messages\ on the smtp transport, and | |
423 | that limit was reached. This would show as a sequence of messages | |
424 | down one connection, then another sequence down a new connection, etc. | |
425 | ||
426 | (3) Exim tried to pass on the SMTP connection to another message, but | |
427 | that message was in the process of being delivered to \(aol.com)\ by some | |
428 | other process (typically, a normal queue runner). This will break the | |
429 | sequence, though the other delivery should pass its connection on to | |
430 | other messages if there are any. | |
431 | ||
432 | (4) The folk at \(aol.com)\ changed the MX records so the host names have | |
433 | changed - or a new host has been added. I don't know how likely this is. | |
434 | ||
435 | (5) Exim is not performing as it should in this regard, for some reason. | |
436 | Next time you have mail queued up for \(aol.com)\, try running | |
437 | ||
438 | ==> exim_dumpdb /var/spool/exim wait-remote_smtp | |
439 | ||
440 | to see if those messages are listed among those waiting for the relevant | |
441 | \(aol.com)\ hosts. | |
442 | ||
443 | ||
444 | Q0019: There seems to be a problem in the string expansion code: it doesn't | |
445 | recognize references to headers such as \"${h_to}"\. | |
446 | ||
447 | A0019: The only valid syntax for header references is (for example) \"$h_to:"\ | |
448 | because header names are permitted by RFC 2822 to contain a very wide | |
449 | range of characters. A colon (or white space) is required as the | |
450 | terminator. | |
451 | ||
452 | ||
453 | Q0020: Why do connections to my machine's SMTP port take a long time to respond | |
454 | with the banner, when connections to other ports respond instantly? The | |
455 | delay is sometimes as long as 30 seconds. | |
456 | ||
457 | A0020: These kinds of delay are usually caused by some kind of network problem | |
458 | that affects outgoing calls made by Exim at the start of an incoming | |
459 | connection. Configuration options that cause outgoing calls are: | |
460 | ||
461 | (1) \rfc1413_hosts\ and \rfc1413_query_timeout\ (for \*ident*\ calls). | |
462 | Firewalls sometimes block ident connections so that they time out, | |
463 | instead of refusing them immediately. This can cause this problem. | |
464 | See Q5023 for a discussion of the usefulness of \*ident*\. | |
465 | ||
466 | (2) The \host_lookup\ option, the \host_reject_connection\ option, or a | |
467 | condition in the ACL that runs at connection time requires the | |
468 | remote host's name to be looked up from its IP address. Sometimes | |
469 | these DNS lookups time out. You can get this effect with ACL | |
470 | statements like this: | |
471 | ||
472 | ==> deny hosts = *.x.example | |
473 | ||
474 | If at all possible, you should use IP addresses instead of host | |
475 | names in blocking lists in order to to avoid this problem. | |
476 | ||
477 | You can use the \-bh-\ option to get more information about what is | |
478 | happening at the start of a connection. However, note that the \-bh-\ | |
479 | option does not provide a complete simulation. In particular, no | |
480 | \*ident*\ checks are done, so it won't show up a delay problem that is | |
481 | related to (1) above. | |
482 | ||
483 | ||
484 | Q0021: What does \*failed to create child process to send failure message*\ mean? | |
485 | This is a busy mail server with \smtp_accept_max\ set to 500, but this | |
486 | problem started to occur at about 300 incoming connections. | |
487 | ||
488 | A0021: Some message delivery failed, and when Exim wanted to send a bounce | |
489 | message, it was unable to create a process in which to do so. Probably | |
490 | the limit on the maximum number of simultaneously active processes has | |
491 | been reached. Most OS have some means of increasing this limit, and in | |
492 | some operating systems there is also a limit per uid which can be | |
493 | varied. | |
494 | ||
495 | ||
496 | Q0022: What does \*No transport set by system filter*\ in a log line mean? | |
497 | ||
498 | A0022: Your system filter contains a \"pipe"\ or \"save"\ or \"mail"\ command, | |
499 | but you have not set the corresponding option which specifies which | |
500 | transport is to be used. You need to set whichever of | |
501 | \system_filter_pipe_transport\, \system_filter_file_transport\ or | |
502 | \system_filter_reply_transport\ is relevant. | |
503 | ||
504 | ||
505 | Q0023: Why is Exim refusing to relay, saying \*failed to find host name from IP | |
506 | address*\ when I have the sender's IP address in an ACL condition? My | |
507 | configuration contains this ACL statement: | |
508 | ||
509 | ==> accept hosts = lsearch;/etc/mail/relaydomains:192.168.96.0/24 | |
510 | ||
511 | A0023: When checking a host list, the items are tested in left-to-right | |
512 | order. The first item in your list is a lookup on the incoming host's | |
513 | name, so Exim has to determine the name from the incoming IP address in | |
514 | order to perform the test. If it can't find the host name, it can't do | |
515 | the check, so it gives up. You would have discovered what was going | |
516 | on if you had run a test such as | |
517 | ||
518 | ==> exim -bh 192.168.96.131 | |
519 | ||
520 | The solution is to put all explicit IP addresses first in the list. | |
521 | Alternatively, you can split the ACL statement into two like this: | |
522 | ||
523 | ==> accept hosts = lsearch;/etc/mail/relaydomains | |
524 | accept hosts = 192.168.96.0/24 | |
525 | ||
526 | If the host lookup fails, the first \"accept"\ fails, but then the | |
527 | second one is considered. | |
528 | ||
529 | ||
530 | Q0024: When I run \"exim -bd -q10m"\ I get \*PANIC LOG: exec of exim -q failed*\. | |
531 | ||
532 | A0024: This probably means that Exim doesn't know its own path so it can't | |
533 | re-exec itself to do the first queue run. Check the output of | |
534 | ||
535 | ==> exim -bP exim_path | |
536 | ||
537 | ||
538 | Q0025: I can't seem to get a pipe command to run when I include a \"${if"\ | |
539 | expansion in it. This fails: | |
540 | ||
541 | ==> command = perl -T /usr/local/rt/bin/rtmux.pl \ | |
542 | rt-mailgate helpdesk \ | |
543 | ${if eq {$local_part}{rt} {correspond}{action}} | |
544 | ||
545 | A0025: You need some internal quoting in there. Exim expands each individual | |
546 | argument separately. Because you have (necessarily) got spaces in your | |
547 | \"${if"\ item, you have to quote that argument. Try | |
548 | ||
549 | ==> command = perl -T /usr/local/rt/bin/rtmux.pl \ | |
550 | rt-mailgate helpdesk \ | |
551 | "${if eq {$local_part}{rt} {correspond}{action}}" | |
552 | ||
553 | \**Warning:**\ If command starts with an item that requires quoting, | |
554 | you cannot just put it in quotes, because a leading quote means that the | |
555 | entire option setting is being quoted. What you have to do is to quote | |
556 | the entire value, and use internally escaped quotes for the ones you | |
557 | really want. For example: | |
558 | ||
559 | ==> command = "\"${if ....}\" arg1 arg2" | |
560 | ||
561 | Any backslashes in the expansion items will have to be doubled to stop | |
562 | them being interpreted by the string reader. | |
563 | ||
564 | ||
565 | Q0026: I'm trying to get Exim to connect an alias to a pipe, but it always | |
566 | gives error code 69, with the comment \*(could mean service or program | |
567 | unavailable)*\. | |
568 | ||
569 | A0026: If your alias entry looks like this: | |
570 | ||
571 | ==> alias: |"/some/command some parameters" | |
572 | ||
573 | change it to look like this: | |
574 | ||
575 | ==> alias: "|/some/command some parameters" | |
576 | ||
577 | ||
578 | Q0027: What does the error \*Spool file is locked*\ mean? | |
579 | ||
580 | A0027: This is not an error. All it means is that when an Exim delivery | |
581 | process (probably started by a queue runner process) looked at a message | |
582 | in order to start delivering it, it found that another Exim process was | |
583 | already busy delivering it. On a busy system this is quite a common | |
584 | occurrence. If you set \"-skip_delivery"\ in the \log_selector\ option, | |
585 | these messages are omitted from the log. | |
586 | ||
587 | The only time when this message might indicate a problem is if it is | |
588 | repeated for the same message for a very long time. That would suggest | |
589 | that the process that is delivering the message has somehow got stuck. | |
590 | ||
591 | ||
592 | Q0028: Exim is reporting IP addresses as 0.0.0.0 or 255.255.255.255 instead of | |
593 | their correct values. What's going on? | |
594 | ||
595 | A0028: You are using a version of Exim built with gcc on an IRIX box. | |
596 | See Q9502. | |
597 | ||
598 | ||
599 | Q0029: I can't seem to figure out why PAM support doesn't work correctly. | |
600 | ||
601 | A0029: There is a problem using PAM with shadow passwords when the calling | |
602 | program is not running as \/root/\. Exim is normally running as the | |
603 | Exim user when authenticating a remote host. See this posting for one | |
604 | way round the problem: | |
605 | ||
606 | \?http://www.exim.org/mailman/htdig/exim-users/Week-of-Mon-20010917/030371.html?\ | |
607 | ||
608 | Another solution can be found at \?http://www.e-admin.de/pam_exim/?\. | |
609 | ||
610 | PAM 0.72 allows authorization as non-\/root/\, using setuid helper programs. | |
611 | Furthermore, in \(/etc/pam.d/exim)\ you can explicitelly specify that | |
612 | this authorization (using setuid helpers) is only permitted for certain | |
613 | users and groups. | |
614 | ||
615 | ||
616 | Q0030: I'm trying to use a query-style lookup for hosts that are allowed to | |
617 | relay, but it is giving really weird errors. | |
618 | ||
619 | A0030: Does your query contain a colon character? Remember that host lists are | |
620 | colon-separated, so you need to double any colons in the query. This | |
621 | applies even if the query is defined as a macro. | |
622 | ||
623 | ||
624 | Q0031: Exim is rejecting connections from hosts that have more than one IP | |
625 | address, for no apparent reason. | |
626 | ||
627 | A0031: You are using Solaris 7 or earlier, and have \"nis dns files"\ in | |
628 | \(/etc/nsswitch.conf)\. Change this to \"dns nis files"\ to avoid hitting Sun | |
629 | bug 1154236 (a bad interaction between NIS and the DNS). | |
630 | ||
631 | ||
632 | Q0032: Exim is failing to find the MySQL library, even though is it present | |
633 | within \\LD_LIBRARY_PATH\\. I'm getting this error: | |
634 | ||
635 | ==> /usr/local/bin/exim: fatal: libmysqlclient.so.6: open failed: | |
636 | No such file or directory | |
637 | ||
638 | A0032: Exim is suid, and \\LD_LIBRARY_PATH\\ is ignored for suid binaries on a | |
639 | Solaris (and other?) systems. What you should be doing is adding | |
640 | \"-R/local/lib/mysql"\ to the same place in the compilation that you added | |
641 | \"-L/local/lib/mysql"\. This tells the binary where to look without | |
642 | needing a path variable. | |
643 | ||
644 | ||
645 | Q0033: What does the error \*lookup of host "xx.xx.xx" failed in yyy router*\ | |
646 | mean? | |
647 | ||
648 | A0033: You configured a \%manualroute%\ router to send the message to xx.xx.xx. When | |
649 | it tried to look up the IP address for that host, the lookup failed | |
650 | with a permanent error. As this is a manual routing, this is a | |
651 | considered to be a serious error which the postmaster needs to know | |
652 | about (maybe you have a typo in your file), and there is little point | |
653 | in keeping on trying. So it freezes the message. | |
654 | ||
655 | (1) Don't set up routes to non-existent hosts. | |
656 | ||
657 | (2) If you must set up routes to non-existent hosts, and don't want | |
658 | freezing, set the \host_find_failed\ option on the router to do something | |
659 | other than freeze. | |
660 | ||
661 | ||
662 | Q0034: Exim works fine on one host, but when I copied the binary to another | |
663 | identical host, it stopped working (it could not resolve DNS names). | |
664 | ||
665 | A0034: Is the new host running exactly the same operating system? Most | |
666 | importantly, are the versions of the dynamically loaded libraries | |
667 | (files with names like \(libsocket.so.1)\) the same on both systems? If not, | |
668 | that is probably the cause of the problem. Either arrange for the | |
669 | libraries to be the same, or rebuild Exim from source on the new host. | |
670 | ||
671 | ||
672 | Q0035: I set a \"hosts"\ condition in an ACL to do a lookup in a file of IP | |
673 | addresses, but it doesn't work. | |
674 | ||
675 | A0035: Did you remember to put \"net-"\ at the start of the the search type? If | |
676 | you set something like this: | |
677 | ||
678 | ==> accept hosts = lsearch;/some/file | |
679 | ||
680 | Exim searches the file for the host name, not the IP address. You need | |
681 | to set | |
682 | ||
683 | ==> accept hosts = net-lsearch;/some/file | |
684 | ||
685 | to make it use the IP address as the key to the lookup. | |
686 | ||
687 | ||
688 | Q0036: Why do I get the error \*Permission denied: creating lock file hitching | |
689 | post*\ when Exim tries to do a local delivery? | |
690 | ||
691 | A0036: Your configuration specifies that local mailboxes are all held in | |
692 | single directory, via configuration lines like these (taken from the | |
693 | default configuration): | |
694 | ||
695 | ==> local_delivery: | |
696 | driver = appendfile | |
697 | file = /var/mail/$local_part | |
698 | ||
699 | and the permissions on the directory probably look like this: | |
700 | ||
701 | ==> drwxrwxr-x 3 root mail 512 Jul 9 13:48 /var/mail/ | |
702 | ||
703 | Using the default configuration, Exim runs as the local user when doing | |
704 | a local delivery, and it uses a lock file to prevent any other process | |
705 | from updating the mailbox while it is writing to it. With those | |
706 | permissions the delivery process, running as the user, is unable to | |
707 | create a lock file in the \(/var/mail(\ directory. There are two solutions | |
708 | to this problem: | |
709 | ||
710 | (1) Set the \"write"\ and \"sticky bit"\ permissions on the directory, so | |
711 | that it looks like this: | |
712 | ||
713 | ==> drwxrwxrwt 3 root mail 512 Jul 9 13:48 /var/mail/ | |
714 | ||
715 | The \"w"\ allows any user to create new files in the directory, but | |
716 | the \"t"\ bit means that only the creator of a file is able to remove | |
717 | it. This is the same setting as is normally used with the \(/tmp)\ | |
718 | directory. | |
719 | ||
720 | (2) Arrange to run the local_delivery transport under a specific group | |
721 | by changing the configuration to read | |
722 | ||
723 | ==> local_delivery: | |
724 | driver = appendfile | |
725 | file = /var/mail/${local_part} | |
726 | group = mail | |
727 | ||
728 | The delivery process still runs under the user's uid, but with the | |
729 | group set to \"mail"\. The group permission on the directory allows | |
730 | the process to create and remove the lock file. | |
731 | ||
732 | The choice between (1) and (2) is up to the administrator. If the | |
733 | second solution is used, users can empty their mailboxes by updating | |
734 | them, but cannot delete them. | |
735 | ||
736 | If your problem involves mail to \/root/\, see also Q0507. | |
737 | ||
738 | ||
739 | Q0037: I am experiencing mailbox locking problems with Sun's \"mailtool"\ used | |
740 | over a network. | |
741 | ||
742 | A0037: See Q9705 in the Sun-specific section below. | |
743 | ||
744 | ||
745 | Q0038: What does the error message \*error in forward file (filtering not | |
746 | enabled): missing or malformed local part*\ mean? | |
747 | ||
748 | A0038: If you are trying to use an Exim filter, you have forgotten to enable | |
749 | the facility, which is disabled by default. In the \%redirect%\ router | |
750 | (in the Exim run time configuration file) you need to set | |
751 | ||
752 | ==> allow_filter = true | |
753 | ||
754 | to allow a \(.forward)\ file to be used as an Exim filter. If you are not | |
755 | trying to use an Exim filter, then you have put a malformed address in | |
756 | the \(.forward)\ file. | |
757 | ||
758 | ||
759 | Q0039: I have installed Exim, but now I can't mail to \/root/\ any more. Why is | |
760 | this? | |
761 | ||
762 | A0039: Most people set up \/root/\ as an alias for the manager of the host. If | |
763 | you haven't done this, Exim will attempt to deliver to \/root/\ as if it | |
764 | were a normal user. This isn't really a good idea because the delivery | |
765 | process would run as \/root/\. Exim has a trigger guard in the option | |
766 | ||
767 | ==> never_users = root | |
768 | ||
769 | in the default configuration file. This prevents it from running as \/root/\ | |
770 | when doing any deliveries. If you really want to run local deliveries as | |
771 | \/root/\, remove this line, but it would be better to create an alias for | |
772 | \/root/\ instead. | |
773 | ||
774 | ||
775 | Q0040: How can I stop undeliverable bounce messages (e.g. to routeable, but | |
776 | undeliverable, spammer senders) from clogging up the queue for days? | |
777 | ||
778 | A0040: If at all possible, you should try to avoid getting into this situation | |
779 | in the first place, for example, by verifying recipients so that you | |
780 | do not accept undeliverable messages that lead to these bounces. | |
781 | You can, however, configure Exim to discard failing bounce messages | |
782 | early. Just set \ignore_bounce_errors_after\ to specify a (short) time | |
783 | to keep them for. | |
784 | ||
785 | ||
786 | Q0041: What does the message \*unable to set gid=ddd or uid=ddd (euid=ddd): | |
787 | local delivery to ... transport=ttt*\ mean? | |
788 | ||
789 | A0041: Have you remembered to make Exim setuid \/root/\? It needs root privilege if | |
790 | it is to do any local deliveries, because it does them ``as the user''. | |
791 | Note also that the partition from which Exim is running (where the | |
792 | binary is installed) must not have the \nosuid\ mount option set. You | |
793 | can check this by looking at its \(/etc/fstab)\ entry (or \(/etc/vfstab)\, | |
794 | depending on your OS). | |
795 | ||
796 | ||
797 | Q0042: My ISP's mail server is rejecting bounce messages from Exim, complaining | |
798 | that they have no sender. The SMTP trace does indeed show that the | |
799 | sender address is \"<>"\. Why is the Sender on the bounce message empty? | |
800 | ||
801 | A0042: Because the RFCs say it must be. Your ISP is at fault. Send them this | |
802 | extract from RFC 2821 section 6.1 (\*Reliable Delivery and Replies by | |
803 | Email*\): | |
804 | ||
805 | If there is a delivery failure after acceptance of a message, the | |
806 | receiver-SMTP MUST formulate and mail a notification message. This | |
807 | notification MUST be sent using a null (\"<>"\) reverse path in the | |
808 | envelope. The recipient of this notification MUST be the address | |
809 | from the envelope return path (or the ::Return-Path:: header line). | |
810 | However, if this address is null (\"<>"\), the receiver-SMTP MUST NOT | |
811 | send a notification. | |
812 | ||
813 | The reason that bounce messages have no sender is so that they | |
814 | themselves cannot provoke further bounces, as this could lead to a | |
815 | unending exchange of undeliverable messages. | |
816 | ||
817 | ||
818 | Q0043: What does the error \*Unable to get interface configuration: 22 Invalid | |
819 | argument*\ mean? | |
820 | ||
821 | A0043: This is an error that occurs when Exim is trying to find out the all the | |
822 | IP addresses on all of the local host's interfaces. If you have lots of | |
823 | virtual interfaces, this can occur if there are more than around 250 of | |
824 | them. The solution is to set the option \local_interfaces\ to list just | |
825 | those IP addresses that you want to use for making and receiving SMTP | |
826 | connections. | |
827 | ||
828 | ||
829 | Q0044: What does the error \*Failed to create spool file*\ mean? | |
830 | ||
831 | A0044: Exim has been unable to create a file in its spool area in which to | |
832 | store an incoming message. This is most likely to be either a | |
833 | permissions problem in the file hierarchy, or a problem with the uid | |
834 | under which Exim is running, though it could be something more drastic | |
835 | such as your disk being full. | |
836 | ||
837 | If you are running Exim with an alternate configuration file using a | |
838 | command such as \"exim -C altconfig..."\, remember that the use of -C | |
839 | takes away Exim's root privilege. | |
840 | ||
841 | Check that you have defined the spool directory correctly by running | |
842 | ||
843 | ==> exim -bP spool_directory | |
844 | ||
845 | and examining the output. Check the mode of this directory. It should | |
846 | look like this, assuming you are running Exim as user \/exim/\: | |
847 | ||
848 | ==> drwxr-x--- 6 exim exim 512 Jul 16 12:29 /var/spool/exim | |
849 | ||
850 | If there are any subdirectories already in existence, they should have | |
851 | the same permissions, owner, and group. Check also that you haven't got | |
852 | incorrect permissions on superior directories (for example, \(/var/spool)\). | |
853 | Check that you have set up the Exim binary to be setuid \/root/\. It should | |
854 | look like this: | |
855 | ||
856 | ==> -rwsr-xr-x 1 root xxx 502780 Jul 16 14:16 exim | |
857 | ||
858 | Note that it is not just the owner that must be \/root/\, but also the third | |
859 | permission must be \"s"\ rather than \"x"\. | |
860 | ||
861 | ||
862 | Q0045: I see entries in the log that mention two different IP addresses for the | |
863 | same connection. Why is this? For example: | |
864 | ||
865 | ==> H=tip-mp8-ncs-13.stanford.edu ([36.173.0.189]) [36.173.0.156] | |
866 | ||
867 | A0045: The actual IP address from which the call came is the final one. | |
868 | Whenever there's something in parentheses in a host name, it is what the | |
869 | host quoted as the domain part of an SMTP HELO or EHLO command. So in | |
870 | this case, the client, despite being 36.173.0.156, issued the command | |
871 | ||
872 | ==> EHLO [36.173.0.189] | |
873 | ||
874 | when it sent your server the message. This is, of course, very | |
875 | misleading. | |
876 | ||
877 | ||
878 | Q0046: A short time after I start Exim I see a defunct zombie process. What | |
879 | is causing this? | |
880 | ||
881 | A0046: Your system must be lightly loaded as far as mail is concerned. The | |
882 | daemon sets off a queue runner process when it is started, but it only | |
883 | tidies up completed child processes when it wakes up for some other | |
884 | reason. When there's nothing much going on, you occasionally see | |
885 | defunct processes like this waiting to be dealt with. This is | |
886 | perfectly normal. | |
887 | ||
888 | ||
889 | Q0047: On a reboot, or a restart of the mail system, I see the message \*Mailer | |
890 | daemons: exim abandoned: unknown, malformed, or incomplete option | |
891 | -bz sendmail*\. What does this mean? | |
892 | ||
893 | A0047: \-bz-\ is a Sendmail option requesting it to create a `configuration freeze | |
894 | file'. Exim has no such concept and so does not support the option. You | |
895 | probably have a line like | |
896 | ||
897 | ==> /usr/lib/sendmail -bz | |
898 | ||
899 | in some start-up script (e.g. \(/etc/init.d/mail)\) immedately before | |
900 | ||
901 | ==> /usr/lib/sendmail -bd -q15m | |
902 | ||
903 | The first of these lines should be commented out. | |
904 | ||
905 | ||
906 | Q0048: Whenever exim restarts it takes up to 3-5 minutes to start responding on | |
907 | the SMTP port. Why is this? | |
908 | ||
909 | A0048: Something else is hanging onto port 25 and not releasing it. One place | |
910 | to look is \(/etc/inetd.conf)\ in case for any reason an SMTP stream is | |
911 | configured there. | |
912 | ||
913 | ||
914 | Q0049: What does the log message \*no immediate delivery: more than 10 messages | |
915 | received in one connection*\ mean? | |
916 | ||
917 | A0049: A remote MTA sent a number of messages in a single SMTP session. Exim | |
918 | limits the number of immediate delivery processes it creates as a | |
919 | result of a single SMTP connection, in order to avoid creating a zillion | |
920 | processes on systems that can have many incoming connections. If you are | |
921 | dialing in to collect mail from your ISP, you should probably set | |
922 | \smtp_accept_queue_per_connection\ to some number larger than 10, or | |
923 | arrange to start a queue runner for local delivery (using \-ql-\) | |
924 | immediately after collecting the mail. | |
925 | ||
926 | ||
927 | Q0050: I am getting complaints from a customer who uses my Exim server for | |
928 | relaying that they are being blocked with a \*Too many connections*\ | |
929 | error. | |
930 | ||
931 | A0050: See \smtp_accept_max\, \smep_accept_max_per_host\ and \smtp_accept_reserve\. | |
932 | ||
933 | ||
934 | Q0051: When I try \"exim -bf"\ to test a system filter, I received the following | |
935 | error message: \*Filter error: unavailable filtering command "fail" near | |
936 | line 8 of filter file*\. | |
937 | ||
938 | A0051: Use the \-bF-\ option to test system filters. This gives you access to the | |
939 | freeze and fail actions. | |
940 | ||
941 | ||
942 | Q0052: What does \*ridiculously long message header*\ in an error report mean? | |
943 | ||
944 | A0052: There has to be some limit to the length of a message's header lines, | |
945 | because otherwise a malefactor could open an SMTP channel to your host, | |
946 | start a message, and then just send characters continuously until your | |
947 | host ran out of memory. (Exim stores all the header lines in main | |
948 | memory while processing a message). For this reason a limit is imposed | |
949 | on the total amount of memory that can be used for header lines. The | |
950 | default is 1MB, but this can be changed by setting \\HEADER_MAXSIZE\\ in | |
951 | \(Local/Makefile)\ before building Exim. Exceeding the limit provokes | |
952 | the ``ridiculous'' error message. | |
953 | ||
954 | ||
955 | Q0053: Exim on my host responds to a connection with \"220 *****..."\ and | |
956 | won't understand \\EHLO\\ commands. | |
957 | ||
958 | A0053: This is the sign of a Cisco Pix ``Mailguard'' sitting in front of your | |
959 | MTA. Pix breaks ESMTP and only does SMTP. It is a nuisance when you have | |
960 | a secure MTA running on your box. Something like ``no fixup protocol | |
961 | smtp 25'' in the Pix configuration is needed. It may be possible to do | |
962 | this by logging into the Pix (using \^telnet^\ or \^ssh^\) and typing | |
963 | \"no fixup smtp"\ to its console. (You may need to use other commands | |
964 | before or after to set up configuration mode and to activate a changed | |
965 | configuration. Consult your Pix documentation or expert.) See also | |
966 | Q0078. | |
967 | ||
968 | ||
969 | Q0054: I'm getting an Exim configuration error \*unknown rewrite flag | |
970 | character (m) in line 386*\ but I haven't used any flags on my rewriting | |
971 | rules. | |
972 | ||
973 | A0054: You have probably forgotten to quote a replacement string that contains | |
974 | white space. | |
975 | ||
976 | ||
977 | Q0055: What does the error \*Failed to open wait-remote_smtp database: Invalid | |
978 | argument*\ mean? | |
979 | ||
980 | A0055: This is something that happens if you have existing DBM hints files when | |
981 | you install a new version of Exim that is compiled to use a different or | |
982 | upgraded DBM library. The simplest thing to try is | |
983 | ||
984 | ==> rm /var/spool/exim/db/* | |
985 | ||
986 | This removes all the hints files. Exim will start afresh and build new | |
987 | ones. If the symptom recurs, it suggests there is some problem with your | |
988 | DBM library. | |
989 | ||
990 | ||
991 | Q0056: We are using Exim to send mail from our web server. However, whenever a | |
992 | user sends an email it gets sent with the return path (envelope sender) | |
993 | //apache@server_name.com// because the PHP script is running as | |
994 | \/apache/\. | |
995 | ||
996 | A0056: You need to include \/apache/\ in the \trusted_users\ configuration option. | |
997 | Only trusted users are permitted to specify senders when mail is passed | |
998 | to Exim via the command line. | |
999 | ||
1000 | ||
1001 | Q0057: We've got people complaining about attachments that don't show up | |
1002 | as attachments, but are included in the body of the message. | |
1003 | ||
1004 | A0057: These symptoms can be seen when some software passes a CRLF line | |
1005 | terminated message via the command line to an MTA that expects lines to | |
1006 | be terminated by LF only, and so preserves the CRs as data. If you can | |
1007 | identify the software that is doing this, try setting the \-dropcr-\ | |
1008 | option on the command it uses to call Exim. Alternatively, you can set | |
1009 | \drop_cr\ in the configuration file, but then that will apply to all | |
1010 | input. | |
1011 | ||
1012 | ||
1013 | Q0058: What does the error \*failed to open DB file \(/var/spool/exim/db/retry)\: | |
1014 | File exists*\ mean? | |
1015 | ||
1016 | A0058: This error is most often caused when a hints file that was written with | |
1017 | one version of the Berkeley DB library is read by another version. | |
1018 | Sometimes this can happen if you change from a binary version of Exim to | |
1019 | a locally compiled version. Or it can happen if you compile and install | |
1020 | a new version of Exim after changing Berkeley DB versions. You can find | |
1021 | out which version your Exim is using by running: | |
1022 | ||
1023 | ==> ldd /usr/sbin/exim | |
1024 | ||
1025 | The solution to the problem is to delete all the files in the | |
1026 | \(/var/spool/exim/db)\ directory, and let Exim recreate them. | |
1027 | ||
1028 | ||
1029 | Q0059: When my Outlook Express 6.0 client sends a STARTTLS command to begin a | |
1030 | TLS session, Exim doesn't seem to receive it. The Outlook log shows | |
1031 | this: | |
1032 | ||
1033 | ==> SMTP: 14:19:27 [tx] STARTTLS | |
1034 | SMTP: 14:19:27 [rx] 500 Unsupported command. | |
1035 | ||
1036 | but the Exim debugging output shows this: | |
1037 | ||
1038 | ==> SMTP<< EHLO xxxx | |
1039 | SMTP>> 250-yyyy Hello xxxx [nnn.nnn.nnn.nnn] | |
1040 | 250-SIZE 52428800 | |
1041 | 250-PIPELINING | |
1042 | 250-AUTH CRAM-MD5 PLAIN LOGIN | |
1043 | 250-STARTTLS | |
1044 | 250 HELP | |
1045 | SMTP<< QUIT | |
1046 | ||
1047 | A0059: Turn off scanning of outgoing email in Norton Antivirus. If you aren't | |
1048 | running Norton Antivirus, see if you are running some other kind of SMTP | |
1049 | proxying, either on the client or on a firewall between the client and | |
1050 | server. ``Unsupported command'' is not an Exim message. | |
1051 | ||
1052 | ||
1053 | Q0060: Why am I getting the error \*failed to expand \"/data/lists/lists/${lc"\ | |
1054 | for require_files: \"${lc"\ is not a known operator*\ for this setting: | |
1055 | ||
1056 | ==> require_files = MAILMAN_HOME/lists/${lc:$local_part}/config.db | |
1057 | ||
1058 | A0060: The value of \"require_files"\ is a \*list*\ in which each item is | |
1059 | separately expanded. You need either to double the colon, or switch to | |
1060 | a different list separator. | |
1061 | ||
1062 | ||
1063 | Q0061: What does the error \*Too many ``Received'' headers - suspected mail | |
1064 | loop*\ mean? | |
1065 | ||
1066 | A0061: Whenever a message passes through an MTA, a ::Received:: header gets | |
1067 | added. Exim counts the number of these headers in incoming messages. If | |
1068 | there are more than the value of \received_headers_max\ (default 30), | |
1069 | Exim assumes there is some kind of mail routing loop occurring. For | |
1070 | example, host A passes the message to host B, which immediately passes | |
1071 | it back to host A. Check the ::Received:: headers and the mail logs to | |
1072 | determine exactly what is going on. | |
1073 | ||
1074 | One common cause of this problem is users with accounts on both systems | |
1075 | who set up each one to forward to the other, thinking that will cause | |
1076 | copies of all messages to be delivered on both of them. | |
1077 | ||
1078 | ||
1079 | Q0062: When I try to start an Exim daemon it crashes. I ran a debugger and | |
1080 | discovered that the crash is happening in the function \^^getservbyname()^^\. | |
1081 | What's going on? | |
1082 | ||
1083 | A0062: What have you got in the file \(/etc/nsswitch.conf)\? If it contains this | |
1084 | line: | |
1085 | ||
1086 | ==> services: db files | |
1087 | ||
1088 | try removing the \"db"\. (Your system is trying to look in some kind of | |
1089 | database before searching the file \(/etc/services)\.) | |
1090 | ||
1091 | ||
1092 | Q0063: When I try to start an Exim daemon, nothing happens. There is no | |
1093 | process, and nothing is written to the Exim log. | |
1094 | ||
1095 | A0063: Check to see if anything is written to \(syslog)\. This problem can be | |
1096 | caused by a permission problem that stops Exim from writing to its log | |
1097 | files, especially if you've specified that they should be written | |
1098 | somewhere other than under Exim's spool directory. You could also try | |
1099 | running the daemon with debugging turned on. | |
1100 | ||
1101 | ||
1102 | Q0064: When I run \"exim -d test@domain"\ it delivers fine, but when I send a | |
1103 | message from the \^mail^\ command, I get \*User unknown*\ and the mail | |
1104 | is saved in \(dead.letter)\. | |
1105 | ||
1106 | A0064: It looks as if Exim isn't being called by \^mail^\; instead it is | |
1107 | calling some other program (probably Sendmail). Try running the command | |
1108 | ||
1109 | ==> /usr/sbin/sendmail -bV | |
1110 | ||
1111 | (If you get \*No such file or directory*\ or \*Command not found*\ you | |
1112 | are running Solaris or IRIX. Try again with \(/usr/lib/sendmail)\.) The | |
1113 | output should be something like this: | |
1114 | ||
1115 | ==> Exim version 4.05 #1 built 13-Jun-2002 10:27:15 | |
1116 | Copyright (c) University of Cambridge 2002 | |
1117 | ||
1118 | If you don't see this, your Exim installation isn't fully operational. | |
1119 | If you are running FreeBSD, see Q9201. For other systems, see Q0114. | |
1120 | ||
1121 | ||
1122 | Q0065: When (as \/root/\) I use -C to run Exim with an alternate configuration | |
1123 | file, it gives an error about being unable to create a spool file when | |
1124 | trying to run an \%autoreply%\ transport. Why is this? | |
1125 | ||
1126 | A0065: When Exim is called with -C, it passes on -C to any instances of itself | |
1127 | that it calls (so that the whole sequence uses the same config file). If | |
1128 | it's running as \/exim/\ when it does this, all is well. However, if it | |
1129 | happens as a consequence of a non-privileged user running \%autoreply%\, | |
1130 | the called Exim gives up its root privilege. Then it can't write to the | |
1131 | spool. | |
1132 | ||
1133 | This means that you can't use -C (even as \/root/\) to run an instance of | |
1134 | Exim that is going to try to run \%autoreply%\ from a process that is | |
1135 | neither \/root/\ nor \/exim/\. Because of the architecture of Exim (using | |
1136 | re-execs to regain privilege), there isn't any way round this | |
1137 | restriction. Therefore, the only way you can make this scenario work is | |
1138 | to run the \%autoreply%\ transport as \/exim/\ (that is, the user that | |
1139 | owns the Exim spool files). This may be satisfactory for autoreplies | |
1140 | that are essentially system-generated, but of course is no good for | |
1141 | autoreplies from unprivileged users, where you want the \%autoreply%\ | |
1142 | transport to be run as the user. To get that to work with an alternate | |
1143 | configuration, you'll have to use two Exim binaries, with different | |
1144 | configuration file names in each. See S001 for a script that patches | |
1145 | the configuration name in an Exim binary. | |
1146 | ||
1147 | ||
1148 | Q0066: What does the message \*unable to set gid=xxx or uid=xxx*\ mean? | |
1149 | ||
1150 | A0066: This message is given when an Exim process is unable to change uid or | |
1151 | gid when it needs to, because it does not have root privilege. This is a | |
1152 | serious problem that prevents Exim from carrying on with what it is | |
1153 | doing. The two most common situations where Exim needs to change uid/gid | |
1154 | are doing local deliveries and processing users' filter files. There are | |
1155 | two common causes of this error: | |
1156 | ||
1157 | (1) You have forgotten to make the exim binary setuid to \/root/\. This | |
1158 | means that it can never change uid/gid in any situation. Also, the | |
1159 | setuid binary must reside on a disk partition that does not have the | |
1160 | \"nosuid"\ mount option set. | |
1161 | ||
1162 | (2) The exim binary is setuid, but you have configured Exim so that, | |
1163 | while trying to verify an address at SMTP time, it runs a router | |
1164 | that needs to change uid/gid. Because Exim runs as \/exim/\ and not | |
1165 | \/root/\ while receiving messages, the router is unable to change | |
1166 | uid and therefore it cannot operate. The usual example of this is a | |
1167 | \%redirect%\ router for users' filter files. | |
1168 | ||
1169 | Setting the \user\ or \check_local_user\ options on a \redirect\ | |
1170 | router causes this to happen (except in the special case when the | |
1171 | redirection list is provided by the \data\ option and does not | |
1172 | contain \":include:"\). | |
1173 | ||
1174 | The solution is to set \no_verify\ on the router that is causing the | |
1175 | problem. This means that it is skipped when an address is being | |
1176 | verified. In ``normal'' configurations where the router is indeed | |
1177 | handling users' filter files, this is quite acceptable, because you | |
1178 | do not usually need to process a filter file in order to verify that | |
1179 | the local part is valid. See, for example, the \%userforward%\ | |
1180 | router in the default configuration. | |
1181 | ||
1182 | ||
1183 | Q0067: What does the error \*too many unrecognized commands*\ mean? | |
1184 | ||
1185 | A0067: There have been instances of network abuse involving mail sent out by | |
1186 | web servers. In most cases, unrecognizable commands are sent as part of | |
1187 | the SMTP session. A real MTA never sends out such invalid commands. Exim | |
1188 | allows a few unrecognized commands in a session to permit humans who are | |
1189 | testing to make a few typos (it responds with a 5xx error). However, if | |
1190 | Exim receives too many such commands, it assumes that it is dealing with | |
1191 | an abuse of some kind, and so it drops the connection. | |
1192 | ||
1193 | ||
1194 | Q0068: Exim times out when trying to connect to some hosts, though those hosts | |
1195 | are known to be up and running. What's the problem? | |
1196 | ||
1197 | A0068: There could be a number of reasons for this (see also Q0017). The | |
1198 | obvious one is that there is a networking problem between the hosts. | |
1199 | If you can ping between the hosts or connect in other ways, the problem | |
1200 | might be caused by ECN (Explicit Congestion Notification) being enabled | |
1201 | in your kernel. ECN uses TCP flags originally assigned to TOS - it's a | |
1202 | "new" invention, and some hosts and routers are known to be confused if | |
1203 | a client uses it. If you are running Linux, you can turn ECN off by | |
1204 | running this command: | |
1205 | ||
1206 | ==> /bin/echo "0" > /proc/sys/net/ipv4/tcp_ecn | |
1207 | ||
1208 | This has also been reported to cure web connection problems from Mozilla | |
1209 | and Netscape browsers in Linux when there were no problems with Windows | |
1210 | Netscape browsers. | |
1211 | ||
1212 | ||
1213 | Q0069: What does the error \*SMTP data timeout (message abandoned) on connection | |
1214 | from...*\ mean? | |
1215 | ||
1216 | A0069: It means that there was a timeout while Exim was reading the contents of | |
1217 | a message on an incoming SMTP connection. That is, it had successfully | |
1218 | accepted a MAIL command, one or more RCPT commands, and a DATA command, | |
1219 | and was in the process of reading the data itself. The length of timeout | |
1220 | is controlled by the \smtp_receive_timeout\ option. | |
1221 | ||
1222 | If you get this error regularly, the cause may be incorrect handling of | |
1223 | large packets by a router or firewall. The maximum size of a packet is | |
1224 | restricted on some links; routers should split packets that are larger. | |
1225 | There is a feature called ``path MTU discovery'' that enables a sender | |
1226 | to discover the maximum packet size over an entire path (multiple | |
1227 | Internet links). This can be broken by misconfigured firewalls and | |
1228 | routers. There is a good explanation at \?http://www.netheaven.com/pmtu.html?\. | |
1229 | Reducing the MTU on your local network can sometimes work round this | |
1230 | problem. See Q0017 (3) for further discussion. | |
1231 | ||
1232 | ||
1233 | Q0070: What does the error \*SMTP command timeout on connection from...*\ mean? | |
1234 | ||
1235 | A0070: Exim was expecting to read an SMTP command from the client, but no | |
1236 | command was read within the \smtp_receive_timeout\ time limit. | |
1237 | ||
1238 | ||
1239 | Q0071: What does the error \*failed to open DB file \(/var/spool/exim//db/retry)\: | |
1240 | Illegal argument*\ mean? | |
1241 | ||
1242 | A0071: See Q0058. The cause of this error is usually the same. | |
1243 | ||
1244 | ||
1245 | Q0072: Exim will deliver to normal aliases, and aliases that are pipes or | |
1246 | files, but it objects to aliases that involve \":include:"\ items, | |
1247 | complaining that it can't change gid or uid. Why is this? | |
1248 | ||
1249 | A0072: See Q0066 for a general answer. The problem happens during verification | |
1250 | of an incoming SMTP message, not during delivery itself. In this | |
1251 | particular case, you must have set up your aliasing router with a \user\ | |
1252 | setting. This causes Exim to change uid/gid when reading \":include:"\ | |
1253 | files. If you do not need the detailed verification provided by the | |
1254 | router, the easy solution is to set \no_verify\ so that the router isn't | |
1255 | used during verification. | |
1256 | ||
1257 | Otherwise, if you set \user\ on the router in order to provide a user | |
1258 | for delivery to pipes or files, one solution is to put the \user\ | |
1259 | setting on the transports instead of on the router. You may need to | |
1260 | create some special transports just for this router. The alternative is | |
1261 | to supply two different routers, one with \user\ and \no_verify\, and | |
1262 | the with \verify_only\ but no \user\ setting. | |
1263 | ||
1264 | ||
1265 | Q0073: I'm seeing log file corruption, with parts of log lines getting mangled | |
1266 | by other log entries. | |
1267 | ||
1268 | A0073: The only time this has been seen is when several servers were writing to | |
1269 | the same log files over NFS. Exim assumes that its log file is on local | |
1270 | disk, and using NFS, especially for more than one server, will not work. | |
1271 | ||
1272 | ||
1273 | Q0074: What does the error message \*remote delivery process count got out of | |
1274 | step*\ mean? | |
1275 | ||
1276 | A0074: Exim uses subprocesses for remote deliveries; this error means that the | |
1277 | master process expected to have a child process running, but found there | |
1278 | were none. Prior to release 4.11, this error could be caused by running | |
1279 | Exim under \^strace^\ on a Linux system, because stracing causes | |
1280 | children to be ``stolen'' such that a parent that tries to wait for | |
1281 | ``any of my children'' is told that it has none. Current releases of | |
1282 | Exim have code to get round this problem. | |
1283 | ||
1284 | ||
1285 | Q0075: I'm using LDAP, and some email addresses that contain special characters | |
1286 | are causing parsing errors in my LDAP lookups. | |
1287 | ||
1288 | A0075: You should be using \"${quote_ldap:$local_part}"\ instead of just | |
1289 | \"$local_part"\ in your lookups. | |
1290 | ||
1291 | ||
1292 | Q0076: I've configured Exim to use \^syslog^\ for its logs, with the main and | |
1293 | reject logs sent to different files, but whenever a message is rejected, | |
1294 | I get one message on the reject log and two messages on the main log. | |
1295 | ||
1296 | A0076: You are probably putting your reject items into the main log as well; | |
1297 | remember \^syslog^\ levels are inclusive (for example, \"mail.info"\ | |
1298 | includes all higher levels, so a \"mail.notice"\ message will be caught | |
1299 | by a \"mail.info"\ descriptor). | |
1300 | Test this by running the command: | |
1301 | ||
1302 | ==> logger -p mail.notice test | |
1303 | ||
1304 | and seeing which logs it goes into. | |
1305 | ||
1306 | ||
1307 | Q0077: I've installed Exim and it is delivering mail just fine. However, when I | |
1308 | try to read mail from my PC I get \*connection rejected*\ or \*unable to | |
1309 | connect*\. | |
1310 | ||
1311 | A0077: See Q5021. | |
1312 | ||
1313 | ||
1314 | Q0078: Exim is logging the unknown SMTP command \"XXXX"\ from my client hosts, | |
1315 | and they are unable to authenticate. | |
1316 | ||
1317 | A0078: This is a sign of a Cisco PIX firewall getting in the way. It does not | |
1318 | support ESMTP, and turns EHLO commands into XXXX. You should configure | |
1319 | the Pix to leave SMTP alone; see Q0053 for how to do this. | |
1320 | ||
1321 | ||
1322 | Q0079: Our new PIX firewall is causing problems with incoming mail. How can | |
1323 | this be fixed? | |
1324 | ||
1325 | A0079: See Q0053 and Q0078. If some messages get through and others do not, | |
1326 | see also Q0017. | |
1327 | ||
1328 | ||
1329 | Q0080: Am I to understand that the database lookups must only return one value? | |
1330 | They can not return a list of values? The documentation seems to | |
1331 | indicate that it's possible to return a list. | |
1332 | ||
1333 | A0080: Lookups can be used in two different situations, and what they return is | |
1334 | different in the two cases. (Be thankful Exim 3 is gone; there was yet | |
1335 | another case!) | |
1336 | ||
1337 | (1) You can use a lookup in any expanded string. The syntax is | |
1338 | ||
1339 | ==> ${lookup ..... } | |
1340 | ||
1341 | In this case, whatever is looked up replaces the expansion item. It | |
1342 | may be one value or a list of values. Whether a single value or a | |
1343 | list is acceptable or not depends on where you are using the string | |
1344 | expansion. If it is for an option that expects just one value, then | |
1345 | only one value is allowed (for example). | |
1346 | ||
1347 | (2) You can make use of the lookup mechanism to test whether something | |
1348 | (typically a host name or IP address) is in a list. For example, | |
1349 | ||
1350 | ==> hosts = a : b : c | |
1351 | ||
1352 | in an ACL tests whether the calling host's name matches ``a'', or | |
1353 | ``b'', or ``c''. Now, suppose you want to keep the list of names in | |
1354 | a database, or cdb file, or NIS map, or... By writing | |
1355 | ||
1356 | ==> hosts = pgsql;select .... | |
1357 | ||
1358 | you are saying to Exim: ``Run this lookup; if it succeeds, behave as | |
1359 | if the host is in the list; if it fails, the host is not in the | |
1360 | list.'' You are using the indexing mechanism of the database as a | |
1361 | fast way of checking a list. A simpler example is | |
1362 | ||
1363 | ==> hosts = lsearch;/some/file | |
1364 | ||
1365 | where the file contains the list of hosts to be searched. | |
1366 | ||
1367 | The complication happens when a list is first expanded before being | |
1368 | interpreted as a list. This happens in a lot of cases. You can therefore | |
1369 | write either of these: | |
1370 | ||
1371 | ==> hosts = cdb;/some/file | |
1372 | hosts = ${lookup{something}cdb{/some/file}} | |
1373 | ||
1374 | but they have different meanings. The first means ``see if the host name | |
1375 | is in the list in this file''. The second means ``run this lookup and | |
1376 | use the result of the lookup as a list of host items to check''. In the | |
1377 | second case, the list could contain multiple values (colon separated), | |
1378 | and one of those values could even be ``cdb;/some/file''. | |
1379 | ||
1380 | Flexibility does lead to complexity, I'm afraid. | |
1381 | ||
1382 | ||
1383 | Q0081: What does \*error in redirect data: included file xxxx is too big*\ | |
1384 | mean? | |
1385 | ||
1386 | A0081: You are trying to include a very large file in a redirection list, using | |
1387 | the \":include:"\ feature. Exim has a built-in limit on the size, as a | |
1388 | safety precaution. The default is 1 megabyte. If you want to increase | |
1389 | this, you have to rebuild Exim. In your \(Local/Makefile)\, put | |
1390 | ||
1391 | ==> MAX_INCLUDE_SIZE = whatever | |
1392 | ||
1393 | and then rebuild Exim. The value is a number of bytes, but you can give | |
1394 | it as a parenthesized arithmetic expression such as \"(3*1024*1024)"\. | |
1395 | However, an included file of more than a megabyte is likely to be quite | |
1396 | inefficient. How many addresses does yours contain? You get the best | |
1397 | performance out of Exim if you arrange to send mailing list messages | |
1398 | with no more than about 100 recipients (in order to get parallelism in | |
1399 | the routing). | |
1400 | ||
1401 | ||
1402 | Q0082: What does \*relocation error: /lib/libnss_dns.so.2: symbol | |
1403 | __libc_res_nquery, version GLIBC_PRIVATE not defined in file | |
1404 | libresolv.so.2 with link time reference*\ mean? | |
1405 | ||
1406 | A0082: You have updated \^glibc^\ while an Exim daemon is running. Stop and | |
1407 | restart the daemon. | |
1408 | ||
1409 | ||
1410 | Q0083: Netscape on Unix is sending messages containing an unqualified user name | |
1411 | in the ::Sender:: header line, which Exim is rejecting because I have | |
1412 | set \"verify = header_syntax"\. How can I fix this? | |
1413 | ||
1414 | A0083: The only thing you can do in Exim is to set the | |
1415 | \sender_unqualified_hosts\ option to allow unqualified sender addresses | |
1416 | form the relevant hosts; of course, this applies to all sender | |
1417 | addresses, not just the ::Sender:: header line. | |
1418 | ||
1419 | Alternatively, you can configure Netscape not to include the header line | |
1420 | in the first place. Add the following line to the | |
1421 | \($HOME/.netscape/preferences.js)\ and \($HOME/.netscape/liprefs.js)\ | |
1422 | files: | |
1423 | ||
1424 | ==> user_pref("mail.suppress_sender_header", true); | |
1425 | ||
1426 | Netscape \*must*\ be shutdown while doing this. | |
1427 | ||
1428 | ||
1429 | Q0084: I want to set up an alias that pipes a message to \^gpg^\ and then pipes | |
1430 | the result to \^mailx^\ to resubmit the message, but when I use my | |
1431 | tested command in an alias file, I get an error from \^gpg^\. | |
1432 | ||
1433 | A0084: Probably you are using a shell command with two pipe symbols in it. An | |
1434 | alias like this: | |
1435 | ||
1436 | ==> gpg-xxx: "|gpg <options> | mailx <options" | |
1437 | ||
1438 | does not work, because Exim does not run pipes under a shell by default. | |
1439 | You must call a shell explicitly if you want to make use of the shell's | |
1440 | features for double-piping, either by piping to \"/bin/sh"\ with a | |
1441 | suitable \"-c"\ option, or by piping to a shell script. | |
1442 | ||
1443 | ||
1444 | Q0085: I see a lot of \*rejected EHLO ... syntactically invalid argument(s)*\. | |
1445 | I know it's because of the underscore in the host name, but is there a | |
1446 | switch to allow Exim to accept mail from such hosts? | |
1447 | ||
1448 | A0085: Yes. Add this to your configuration: | |
1449 | ||
1450 | ==> helo_allow_chars = _ | |
1451 | ||
1452 | For more seriously malformed host names, see \helo_accept_junk_hosts\. | |
1453 | See also Q0732. | |
1454 | ||
1455 | ||
1456 | Q0086: What does \*SMTP protocol violation: synchronization error (next input | |
1457 | sent too soon)*\ mean? | |
1458 | ||
1459 | A0086: SMTP is a ``lock-step'' protocol, which means that, at certain points in | |
1460 | the protocol, the client must wait for the server to respond before | |
1461 | sending more data. Exim checks for correct behaviour, and issues this | |
1462 | error if the client sends data too soon. This protects against | |
1463 | malefactious clients who send a bunch of SMTP commands (usually to | |
1464 | transmit spam) without waiting for any replies. | |
1465 | ||
1466 | This error is also provoked if the client is trying to start up a TLS | |
1467 | session immediately on connection, without using the STARTTLS command. | |
1468 | See Q1707 for a discussion of this case. | |
1469 | ||
1470 | ||
1471 | Q0087: What does \*rejected after DATA: malformed address: xx@yy may not follow | |
1472 | <xx@yy> : failing address in "from" header*\ mean? (I've obscured the | |
1473 | real email addresses.) | |
1474 | ||
1475 | A0087: Your DATA ACL contains | |
1476 | ||
1477 | ==> verify = header_syntax | |
1478 | ||
1479 | and an incoming message contained the line | |
1480 | ||
1481 | ==> From: xx@yy <xx@yy> | |
1482 | ||
1483 | This is syntactically invalid. The contents of an address in a header | |
1484 | line are either just the address, or a ``phrase'' followed by an address | |
1485 | in angle brackets. In the latter case, the ``phrase'' must be quoted if | |
1486 | it contains special characters such as @. The following are valid | |
1487 | versions of the bad header: | |
1488 | ||
1489 | ==> From: xx@yy | |
1490 | From: "xx@yy" <xx@yy> | |
1491 | ||
1492 | though why on earth anything generates this kind of redundant nonsense I | |
1493 | can't think. | |
1494 | ||
1495 | ||
1496 | Q0088: The Windows mailer SENDFILE.EXE sometimes hangs while trying to send a | |
1497 | message to Exim 4, and eventually times out. It worked flawlessly with | |
1498 | Exim 3. What has changed? | |
1499 | ||
1500 | A0088: Exim 4 sets an obscure TCP/IP parameter called TCP_NODELAY. This | |
1501 | disables the "Nagle algorithm" for the TCP/IP transmission. The Nagle | |
1502 | algorithm can improve network performance in interactive situations such | |
1503 | as a human typing at a keyboard, by buffering up outgoing data until the | |
1504 | previous packet has been acknowledged, and thereby reducing the number | |
1505 | of packets used. This is not relevant for mail transmission, which | |
1506 | mostly consists of quite large blocks of data; setting TCP_NODELAY | |
1507 | should improve performance. However, it seems that some Windows clients | |
1508 | do not function correctly if the server turns off the Nagle algorithm. | |
1509 | If you are using Exim 4.23 or later, you can set | |
1510 | ||
1511 | ==> tcp_nodelay = false | |
1512 | ||
1513 | This stops Exim setting TCP_NODELAY on the sockets created by the | |
1514 | listening daemon. | |
1515 | ||
1516 | ||
1517 | Q0089: What does the error \*kernel: application bug: exim(12099) has SIGCHLD | |
1518 | set to SIG_IGN but calls wait()*\ mean? | |
1519 | ||
1520 | A0089: This was a bad interaction between a relatively recent change to the | |
1521 | Linux kernel and some ``belt and braces'' programming in Exim. The | |
1522 | following explanation is taken from Exim's change log: | |
1523 | ||
1524 | When Exim is receiving multiple messages on a single connection, and | |
1525 | spinning off delivery processess, it sets the SIGCHLD signal handling to | |
1526 | SIG_IGN, because it doesn't want to wait for these processes. However, | |
1527 | because on some OS this didn't work, it also has a paranoid call to | |
1528 | \^waitpid()^\ in the loop to reap any children that have finished. Some | |
1529 | versions of Linux now complain (to the system log) about this | |
1530 | ``illogical'' call to \^waitpid()^\. I have therefore put it inside a | |
1531 | conditional compilation, and arranged for it to be omitted for Linux. | |
1532 | ||
1533 | I am pretty sure I caught all the places in Exim where this happened. | |
1534 | However, there are still occasional reports of this error. I have not | |
1535 | heard of any resolutions, but my current belief is that they are caused | |
1536 | by something that Exim calls falling foul of the same check. There was | |
1537 | at one time a suspicion that the IPv6 stack was involved. | |
1538 | ||
1539 | ||
1540 | Q0090: I can't seem to get a pipe command to run when I include a \"${lookup"\ | |
1541 | expansion in it. | |
1542 | ||
1543 | A0090: See Q0025. | |
1544 | ||
1545 | ||
1546 | Q0091: Why is Exim giving the error \*Failed to send message from address_reply | |
1547 | transport*\ when I run it using -C to specify an alternate | |
1548 | configuration? | |
1549 | ||
1550 | A0091: See Q0065. | |
1551 | ||
1552 | ||
2683a02a PH |
1553 | Q0092: Exim crashes when I try to start the daemon, but works fine otherwise. |
1554 | ||
1555 | A0092: There was a known problem (a db incompatibility) that made the function | |
1556 | \^^getservbyname()^^\ crash in some operating systems. See, for | |
1557 | instance: | |
1558 | ||
1559 | \?http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=129025?\ | |
1560 | ||
1561 | The workaround in Exim is to set | |
1562 | ||
1563 | ==> daemon_smtp_port = 25 | |
1564 | ||
1565 | in the configuration, to stop Exim calling the failing function. | |
1566 | ||
1567 | ||
1568 | Q0093: The error message \*Program received signal SIGINT, Interrupt.*\ occurs | |
1569 | when I try to use Exim with PostgreSQL. | |
1570 | ||
1571 | A0093: Check that you have not set | |
1572 | ||
1573 | ==> log_statement=true | |
1574 | ||
1575 | in the PostgreSQL configuration file. It seems that this causes | |
1576 | PostgreSQL to return logging information as the first row in a query | |
1577 | result, which totally confuses Exim. | |
1578 | ||
1579 | ||
495ae4b0 PH |
1580 | |
1581 | 1. BUILDING AND INSTALLING | |
1582 | ||
1583 | Q0101: I'm having a problem with an Exim RPM. | |
1584 | ||
1585 | A0101: Normally the thing to do if you have a problem with an RPM package is | |
1586 | to contact the person who built the package first, not the person who | |
1587 | made the software that's in the package. You can usually find out who | |
1588 | made a package using the following command: | |
1589 | ||
1590 | ==> rpm --query --package --queryformat '%{PACKAGER}\n' <rpm-package-file> | |
1591 | ||
1592 | where \[rpm-package-file]\ is the actual file, e.g. \(exim-3.03-2.i386.rpm)\. | |
1593 | Or, if the package is installed on your system: | |
1594 | ||
1595 | ==> rpm --query --queryformat '%{PACKAGER}\n' <package-name> | |
1596 | ||
1597 | where \[package-name]\ is the name component of the package, e.g. \"exim"\. | |
1598 | If the packager is unable or unwilling to help, only then should you | |
1599 | contact the actual author or associated mailing list of the software. | |
1600 | ||
1601 | If you discover through the querying process that you can't tell who | |
1602 | the person (or company or group) is who built the package, or that they | |
1603 | no longer exist at the given address, then you should reconsider | |
1604 | whether you want a package from an unknown source on your system. | |
1605 | ||
1606 | If you discover through the querying process that you yourself are the | |
1607 | person who built the package, then you should either (a) contact the | |
1608 | author or associated mailing list, or (b) reconsider whether you ought | |
1609 | to be building and distributing RPM packages of software you don't | |
1610 | understand. | |
1611 | ||
1612 | Similar rules of thumb govern other binary package formats, including | |
1613 | debs, tarballs, and POSIX packages. | |
1614 | ||
1615 | ||
1616 | Q0102: I can't get Exim to compile with Berkeley DB version 2.x or 3.x. | |
1617 | ||
1618 | A0102: Have you set \"USE_DB=yes\" in \(Local/Makefile)\? This causes Exim to use the | |
1619 | native interface to the DBM library instead of the compatibility | |
1620 | interface, which needs a header called \(ndbm.h)\ that may not exist on your | |
1621 | system. | |
1622 | ||
1623 | ||
1624 | Q0103: I'm getting an \*undefined symbol*\ error for \"hosts_ctl"\ when I try to | |
1625 | build Exim. (On some systems this error is \*undefined reference to | |
1626 | 'hosts_ctl'*\.) | |
1627 | ||
1628 | A0103: You should either remove the definition of \\USE_TCP_WRAPPERS\\ or add | |
1629 | \"-lwrap"\ to your \\EXTRALIBS\\ setting in Local/Makefile. | |
1630 | ||
1631 | ||
1632 | Q0104: I'm about to upgrade to a new Exim release. Do I need to ensure the | |
1633 | spool is empty, or take any other special action? | |
1634 | ||
1635 | A0104: It depends on where you are coming from. | |
1636 | ||
1637 | (1) If you are changing to release 4.00 or later from a release prior to | |
1638 | 4.00, you will need to make changes to the run time configuration file. | |
1639 | See the file \(doc/Exim4.upgrade)\ for details. If you are coming from | |
1640 | before release 3.00, you should also see \(doc/Exim3.upgrade)\. | |
1641 | ||
1642 | (2) If you are upgrading from an Exim 4 release to a later release, you | |
1643 | do not need to take special action. New releases are made backwards | |
1644 | compatible with old spool files and hints databases, so that upgrading | |
1645 | can be done on a running system. All that should be necessary is to | |
1646 | install a new binary and then HUP the daemon. | |
1647 | ||
1648 | ||
1649 | Q0105: What does the error \*install-info: command not found*\ mean? | |
1650 | ||
1651 | A0105: You have set \\INFO_DIRECTORY\\ in your \(Local/Makefile)\, and Exim is trying | |
1652 | to install the Texinfo documentation, but cannot find the command called | |
1653 | \(install-info)\. If you have a version of Texinfo prior to 3.9, you | |
1654 | should upgrade. Otherwise, check your installation of Texinfo to see why | |
1655 | the \(install-info)\ command is not available. | |
1656 | ||
1657 | ||
1658 | Q0106: Exim doesn't seem to be recognizing my operating system type correctly, | |
1659 | and so is failing to build. | |
1660 | ||
1661 | A0106: Run the command \"scripts/os-type -generic"\. The output should be one of | |
1662 | the known OS types, and should correspond to your operating system. You | |
1663 | can see which OS are supported by obeying \"ls OS/Makefile-*"\ and looking | |
1664 | at the file name suffixes. | |
1665 | ||
1666 | If there is a discrepancy, it means that the script is failing to | |
1667 | interpret the output from the \"uname"\ command correctly, or that the | |
1668 | output is wrong. Meanwhile, you can build Exim by obeying | |
1669 | ||
1670 | ==> EXIM_OSTYPE=xxxx make | |
1671 | ||
1672 | instead of just \"make"\, provided you are running a Bourne-compatible | |
1673 | shell, or otherwise by setting \\EXIM_OSTYPE\\ correctly in your | |
1674 | environment. It is probably best to start again from a clean | |
1675 | distribution, to avoid any wreckage left over from the failed attempt. | |
1676 | ||
1677 | ||
1678 | Q0107: Exim fails to build, complaining about the absence of the \"killpg"\ | |
1679 | function. | |
1680 | ||
1681 | A0107: This function should be present in all modern flavours of Unix. If you | |
1682 | are using an older version, you should be able to get round the problem | |
1683 | by inserting | |
1684 | ||
1685 | ==> #define killpg(pgid,sig) kill(-(pgid),sig) | |
1686 | ||
1687 | into the file called \(OS/os.h-xxx)\, where xxx identifies your operating | |
1688 | system, and is the output of the command \"scripts/os-type -generic"\. | |
1689 | ||
1690 | ||
1691 | Q0108: I'm getting an unresolved symbol \"ldap_is_ldap_url"\ when trying to build | |
1692 | Exim. | |
1693 | ||
1694 | A0108: You must have specified \"LOOKUP_LDAP=yes"\ in the configuration. Have you | |
1695 | remembered to set \"-lldap"\ somewhere (e.g. in \\LOOKUP_LIBS\\)? You need that | |
1696 | in order to get the LDAP library scanned when linking. | |
1697 | ||
1698 | ||
1699 | Q0109: I'm getting an unresolved symbol \"mysql_close"\ when trying to build Exim. | |
1700 | ||
1701 | A0109: You must have specified \"LOOKUP_MYSQL=yes"\ in the configuration. Have you | |
1702 | remembered to set \"-lmysqlclient"\ somewhere (e.g. in \\LOOKUP_LIBS\\)? You | |
1703 | need that in order to get the MySQL library scanned when linking. | |
1704 | ||
1705 | ||
1706 | Q0110: I'm trying to build Exim with PAM support. I have included \"-lpam"\ in | |
1707 | \\EXTRALIBS\\, but I'm still getting a linking error: | |
1708 | ||
1709 | ==> /lib/libpam.so: undefined reference to `dlerror' | |
1710 | /lib/libpam.so: undefined reference to `dlclose' | |
1711 | /lib/libpam.so: undefined reference to `dlopen' | |
1712 | /lib/libpam.so: undefined reference to `dlsym' | |
1713 | ||
1714 | A0110: Add \"-ldl"\ to \\EXTRALIBS\\. In some systems these dynamic loading functions | |
1715 | are in their own library. | |
1716 | ||
1717 | ||
1718 | Q0111: I'm getting the error \*db.h: No such file or directory*\ when I try to | |
1719 | build Exim. | |
1720 | ||
1721 | A0111: This problem has been seen with RedHat 7.0, but could also happen in | |
1722 | other environments. If your system is using the DB library, you | |
1723 | need to install the DB development package in order to build Exim. | |
1724 | The package is called something like \"db3-devel-3.1.14-16.i386.rpm"\ for | |
1725 | Linux systems, but you should check which version of DB you have | |
1726 | installed (current releases are DB 4). | |
1727 | ||
1728 | ||
1729 | Q0112: I'm getting the error \*/usr/bin/ld: cannot find -ldb*\ when I try to | |
1730 | build Exim. | |
1731 | ||
1732 | A0112: This is probably the same problem as Q0111. | |
1733 | ||
1734 | ||
1735 | Q0113: I've compiled Exim and I've managed to start it but there was one | |
1736 | problem - it always complained that \(libmsqlclient.so.10)\ was not found, | |
1737 | even though this file is in \(/usr/local/lib/mysql/)\. | |
1738 | ||
1739 | A0113: Solaris: ensure you have this in your \(Local/Makefile)\: | |
1740 | ||
1741 | ==> LOOKUP_LIBS=-L/usr/local/lib/mysql -R/usr/local/lib/mysql | |
1742 | ||
1743 | Net/Open/FreeBSD: Run this command (or ensure it gets run automatically | |
1744 | at boot time): | |
1745 | ||
1746 | ==> ldconfig -m /usr/local/lib/mysql | |
1747 | ||
1748 | Linux: add \(/usr/local/lib/mysql)\ to \(/etc/ld.so.conf)\ and re-run \(ldconfig)\. | |
1749 | Alternatively, add | |
1750 | ||
1751 | ==> -Wl,-rpath -Wl,/usr/local/lib/mysql | |
1752 | ||
1753 | to EXTRA_LIBS and then re-link (this is similar to the Solaris solution | |
1754 | above). This will probably also work on other systems that use GNU | |
1755 | Binutils. | |
1756 | ||
1757 | ||
1758 | Q0114: How can I remove Sendmail from my system? I've built Exim and run \"make | |
1759 | install"\, but it still doesn't seem to be fully operational. | |
1760 | ||
1761 | A0114: If you are running FreeBSD, see Q9201. Otherwise, you need to arrange | |
1762 | that whichever of the paths \(/usr/sbin/sendmail)\ or \(/usr/lib/sendmail)\ | |
1763 | exists on your system is changed to refer to Exim. For example, you | |
1764 | could use these commands (as \/root/\): | |
1765 | ||
1766 | ==> mv /usr/sbin/sendmail /usr/sbin/sendmail.original | |
1767 | chmod u-s /usr/sbin/sendmail.original | |
1768 | ln -s /path/to/exim /usr/sbin/sendmail | |
1769 | ||
1770 | The second command removes the setuid privilege from the old MTA, as a | |
1771 | general safety precaution. In the third command, substitute the actual | |
1772 | path to the Exim binary for \(/path/to/exim)\. | |
1773 | ||
1774 | ||
1775 | Q0115: What does \*Can't open \(../scripts/newer)\: No such file or directory*\ | |
1776 | mean? I got it while trying to build Exim. | |
1777 | ||
1778 | A0115: You are using FreeBSD, or another OS that has a \^make^\ command which | |
1779 | tries to optimize the running of commands. Exim's \(Makefile)\ contains | |
1780 | targets with sequential commands like this: | |
1781 | ||
1782 | ==> buildpcre: | |
1783 | @cd pcre; $(MAKE) SHELL=$(SHELL) AR="$(AR)" $(MFLAGS) CC="$(CC)" \ | |
1784 | CFLAGS="$(CFLAGS) $(PCRE_CFLAGS)" \ | |
1785 | RANLIB="$(RANLIB)" HDRS="$(PHDRS)" \ | |
1786 | INCLUDE="$(INCLUDE) $(IPV6_INCLUDE) $(TLS_INCLUDE)" | |
1787 | @if $(SHELL) $(SCRIPTS)/newer pcre/libpcre.a exim; then \ | |
1788 | /bin/rm -f exim eximon.bin; fi | |
1789 | ||
1790 | The second command assumes that the \"cd pcre"\ in the first command is | |
1791 | no longer in effect. If you have \"-j3"\ in your default set of | |
1792 | \"MAKEFLAGS"\, FreeBSD \^make^\ tries to optimize, and ends up up with both | |
1793 | commands in the same shell process. The result is that \"$(SCRIPTS)"\ | |
1794 | (which has a value of \"../scripts"\) is not found. | |
1795 | ||
1796 | The simplest solution is to force \^make^\ to use backwards compatibility | |
1797 | mode with each command in its own shell, by using the \-B\ flag. To | |
1798 | ensure that this happens throughout the build, it's best to export it in | |
1799 | your environment: | |
1800 | ||
1801 | ==> MAKEFLAGS='-B' | |
1802 | export MAKEFLAGS | |
1803 | make | |
1804 | ||
1805 | ||
1806 | Q0116: I have tried to build Exim with Berkeley DB 3 and 4, but I always get | |
1807 | errors. | |
1808 | ||
1809 | A0116: One common problem, especially when you have several different versions | |
1810 | of BDB installed on the same host, is that the header files and library | |
1811 | files for BDB are not in a standard place. You therefore need to tell | |
1812 | Exim where they are, by setting INCLUDE and DBMLIB in your | |
1813 | \(Local/Makefile)\. For example, I use this on my workstation when | |
1814 | I want to build with DB 4.1: | |
1815 | ||
1816 | ==> INCLUDE=-I/opt/local/include/db-4.1 | |
1817 | DBMLIB=/opt/local/lib/db-4.1/libdb.a | |
1818 | ||
1819 | Specifying the complete library file like this will cause it to be | |
1820 | statically linked with Exim. You'll have to check to see where these | |
1821 | files are on your system. For example, on FreeBSD 5, the header is in | |
1822 | \(/usr/local/include/db4)\ and the library is in \(/usr/local/lib)\ and | |
1823 | called \(libdb4)\. In that environment, you could use: | |
1824 | ||
1825 | ==> INCLUDE=-I/usr/local/include/db4 | |
1826 | DBMLIB=-L/usr/local/lib -ldb4 | |
1827 | ||
1828 | This time, DBMLIB is specifying the library directory (\(/usr/local/lib)\) | |
1829 | and the name of the library (\(db4)\) separately. The name of the actual | |
1830 | library file is \(/usr/local/lib/libdb4.something)\. If the library was | |
1831 | compiled for dynamic linking, that will be used. | |
1832 | ||
1833 | ||
1834 | Q0117: Is there a quick walk-through of an Exim install from source anywhere? | |
1835 | ||
1836 | A0117: Here! This is a contribution from a RedHat user, somewhat edited. On | |
1837 | other operating systems things may be slightly different, but the | |
1838 | general approach is the same. | |
1839 | ||
1840 | (1) Install the db needed for Exim. This needs to be done first if you | |
1841 | don't have a DBM library installed. Go to \?http://www.sleepycat.com?\ | |
1842 | and download \(db-4.1.25.tar.gz)\, or whatever the current release is. | |
1843 | Then: | |
1844 | ||
1845 | ==> gunzip db-4.1.25.tar.gz | |
1846 | tar -xvf db-4.1.25.tar | |
1847 | cd db-4.1.25 | |
1848 | cd build_unix | |
1849 | ../dist/configure | |
1850 | make | |
1851 | make install | |
1852 | ||
1853 | (2) Add a user for use by Exim, unless you want to use an existing user | |
1854 | such as \/mail/\: | |
1855 | ||
1856 | ==> adduser exim | |
1857 | ||
1858 | (3) Now you can prepare to build Exim. Go to \?http://www.exim.org?\ or | |
1859 | one of its mirrors, or the master ftp site | |
1860 | \?ftp://ftp.csx.cam.ac.uk/pub/software/email/exim/exim4?\, and download | |
1861 | \(exim-4.20.tar.gz)\ or whatever the current release is. Then: | |
1862 | ||
1863 | ==> gunzip exim-4.20.tar.gz | |
1864 | tar -xvf exim-4.20.tar | |
1865 | cd exim-4.20 | |
1866 | cp src/EDITME Local/Makefile | |
1867 | cp exim_monitor/EDITME Local/eximon.conf | |
1868 | ||
1869 | (4) Edit \(Local/Makefile)\: | |
1870 | ||
1871 | Comment out EXIM_MONITOR= unless you want to install the Exim | |
1872 | monitor (it requires X-windows). | |
1873 | ||
1874 | Set the user you want Exim to use for itself: | |
1875 | ||
1876 | ==> EXIM_USER=exim | |
1877 | ||
1878 | If your DBM library is Berkeley DB, set up to use its native interface: | |
1879 | ||
1880 | ==> USE_DB=yes | |
1881 | ||
1882 | Make sure Exim's build can find the DBM library and its headers. If | |
1883 | you've installed Berkeley DB 4 you'll need to have settings like this | |
1884 | in \(Local/Makefile)\: | |
1885 | ||
1886 | ==> INCLUDE=-I/usr/local/BerkeleyDB.4.1/include | |
1887 | DBMLIB=/usr/local/BerkeleyDB.4.1/lib/libdb.a | |
1888 | ||
1889 | (Check that the first directory contains the db.h file and that the | |
1890 | second library exists.) | |
1891 | ||
1892 | You don't need to change anything else, but you might want to review | |
1893 | the default settings in the ``must specify'' section. | |
1894 | ||
1895 | (4) Build Exim by running the \/make/\ command. | |
1896 | ||
1897 | (5) Install Exim by running, as \/root/\: | |
1898 | ||
1899 | ==> make install | |
1900 | ||
1901 | You \*must*\ be \/root/\ to do this. You do not have to be root for any of | |
1902 | the previous building activity. | |
1903 | ||
1904 | (6) Run some tests on Exim; see if it will do local and remote | |
1905 | deliveries. Change the configuration if necessary (for example, | |
1906 | uncommenting \group\ on the \%local_delivery%\ transport if you don't | |
1907 | use a ``sticky bit'' directory). | |
1908 | ||
1909 | (7) Change Sendmail to Exim (of course you need to have had Sendmail | |
1910 | installed to do this). | |
1911 | ||
1912 | ==> /etc/init.d/sendmail stop | |
1913 | mv /usr/sbin/sendmail /usr/sbin/sendmail.org | |
1914 | ln -s /usr/exim/bin/exim /usr/sbin/sendmail | |
1915 | /etc/init.d/sendmail start | |
1916 | ||
1917 | (8) Check the Exim log. Either use the Exim monitor, or: | |
1918 | ||
1919 | ==> tail -f /var/spool/exim/log/mainlog | |
1920 | ||
1921 | ||
1922 | Q0118: I've set \"LOOKUP_INCLUDE=-I/client/include"\ in Local/Makefile, but the | |
1923 | compilation of \^exim_dumpdb^\ is ignoring this option and failing. Why? | |
1924 | ||
1925 | A0118: LOOKUP_INCLUDE is the special include file for lookup modules in Exim | |
1926 | (e.g. mysql, LDAP). Confusingly, it doesn't apply to basic DBM code | |
1927 | which is used also for other things. Try setting INCLUDE and DBMLIB | |
1928 | instead. For example: | |
1929 | ||
1930 | ==> USE_DB=yes | |
1931 | INCLUDE=-I/client/include | |
1932 | DBMLIB=/client/lib/libdb.a | |
1933 | ||
1934 | ||
1935 | Q0119: I know there are some 3rd-party patches for Exim, for exiscan and | |
1936 | other things. Where are they? | |
1937 | ||
1938 | A0119: Exiscan is at \?http://duncanthrax.net/exiscan-acl/?\. | |
1939 | [[br]] | |
1940 | Scanexi is at \?http://w1.231.telia.com/~u23107873/scanexi.html?\ | |
1941 | [[br]] | |
1942 | A sample \^^local_scan()^^\ function for interfacing to \^uvscan^\ is | |
1943 | at \?http://www.dcs.qmul.ac.uk/~mb/local_scan/?\. | |
1944 | [[br]] | |
1945 | An interface to SpamAssassin at SMTP time is at | |
1946 | \?http://marc.merlins.org/linux/exim/sa.html?\. | |
1947 | [[br]] | |
1948 | A mini-HOWTO (PDF file) about scanning and virus scanning, and some RPMs | |
1949 | can be found at \?http://www.timj.co.uk/linux/exim.php?\. | |
1950 | ||
1951 | ||
1952 | ||
1953 | 2. ROUTING IN GENERAL | |
1954 | ||
1955 | Q0201: How can I arrange that messages larger than some limit are handled by | |
1956 | a special router? | |
1957 | ||
1958 | A0201: You can use a \condition\ option on the router line this: | |
1959 | ||
1960 | ==> condition = ${if >{$message_size}{100K}{yes}{no}} | |
1961 | ||
1962 | ||
1963 | Q0202: Can I specify a list of domains to explicitly reject? | |
1964 | ||
1965 | A0202: Set up a named domain list containing the domains in the first section | |
1966 | of the configuration, for example: | |
1967 | ||
1968 | ==> domainlist reject_domains = list:of:domains:to:reject | |
1969 | ||
1970 | You can use this list in an ACL to reject any SMTP recipients in those | |
1971 | domains. You can also give a customized error message, like this: | |
1972 | ||
1973 | ==> deny message = The domain $domain is no longer supported | |
1974 | domains = +reject_domains | |
1975 | ||
1976 | If you also want to reject these domains in messages that are submitted | |
1977 | from the command line (not using SMTP), you need to set up a router to | |
1978 | do it, like this: | |
1979 | ||
1980 | ==> reject_domains: | |
1981 | driver = redirect | |
1982 | domains = +reject_domains | |
1983 | allow_fail | |
1984 | data = :fail: The domain $domain is no longer supported | |
1985 | ||
1986 | ||
1987 | Q0203: How can I arrange to do my own qualification of non-fully-qualified | |
1988 | domains, and then pass them on to the next router? | |
1989 | ||
1990 | A0203: If you have some list of domains that you want to qualify, you can do | |
1991 | this using a redirect router. For example, | |
1992 | ||
1993 | ==> qualify: | |
1994 | driver = redirect | |
1995 | domains = *.a.b | |
1996 | data = ${quote:$local_part}@$domain.c.com | |
1997 | ||
1998 | This adds \".c.com"\ to any domain that matches \"*.a.b"\. | |
1999 | If you want to do this in conjunction with a \%dnslookup%\ router, the | |
2000 | \widen_domains\ option of that router may be another way of achieving | |
2001 | what you want. | |
2002 | ||
2003 | ||
2004 | Q0204: Every system has a \"nobody"\ account under which httpd etc run. I would | |
2005 | like to know how to restrict mail which comes from that account to users | |
2006 | on that host only. | |
2007 | ||
2008 | A0204: Set up a first router like this: | |
2009 | ||
2010 | ==> fail_nobody: | |
2011 | driver = redirect | |
2012 | senders = nobody@your.domain | |
2013 | domains = ! +local_domains | |
2014 | allow_fail | |
2015 | data = :fail: Nobody may not mail off-site | |
2016 | ||
2017 | This assumes you have defined \+local_domains\ as in the default | |
2018 | configuration. | |
2019 | ||
2020 | ||
2021 | Q0205: How can I get Exim to deliver to me locally and everyone else at the same | |
2022 | domain via SMTP to the MX record specified host? | |
2023 | ||
2024 | A0205: Create an \%accept%\ router to pick off the one address and pass it to | |
2025 | an appropriate transport. Put this router before the one that does MX | |
2026 | routing: | |
2027 | ||
2028 | ==> me: | |
2029 | driver = accept | |
2030 | domains = dom.com | |
2031 | local_parts = me | |
2032 | transport = local_delivery | |
2033 | ||
2034 | In the transport you will have to specify the \user\ option. An | |
2035 | alternative way of doing this is to add a condition to the router that | |
2036 | does MX lookups to make it skip your address. Subsequent routers can then | |
2037 | deliver your address locally. You'll need a condition like this: | |
2038 | ||
2039 | ==> condition = \ | |
2040 | ${if and {{eq{$domain}{dom.com}}{eq{$local_part}{me}}}{no}{yes}} | |
2041 | ||
2042 | ||
2043 | Q0206: How can I get Exim to deliver certain domains to a different SMTP port | |
2044 | on my local host? | |
2045 | ||
2046 | A0206: You must set up a special \%smtp%\ transport, where you can specify the | |
2047 | \port\ option, and then set up a router to route the domains to that | |
2048 | transport. There are two possibilities for specifying the host: | |
2049 | ||
2050 | (1) If you use a \%manualroute%\ router, you can specify the local host | |
2051 | in the router options. You must also set | |
2052 | ||
2053 | ==> self = send | |
2054 | ||
2055 | so that it does not object to sending to the local host. | |
2056 | ||
2057 | (2) If you use a router that cannot specify hosts (for example, an | |
2058 | \%accept%\ router with appropriate conditions), you have to specify | |
2059 | the host using the \hosts\ option of the transport. In this case, | |
2060 | you must also set \allow_localhost\ on the transport. | |
2061 | ||
2062 | ||
2063 | Q0207: Why does Exim lower-case the local-part of a non-local domain when | |
2064 | routing? | |
2065 | ||
2066 | A0207: Because \caseful_local_part\ is not set (in the default configuration) | |
2067 | for the \%dnslookup%\ router. This does not matter because the local | |
2068 | part takes no part in the routing, and the actual local part that is | |
2069 | sent out in the RCPT command is always the original local part. | |
2070 | ||
2071 | ||
2072 | ||
2073 | 3. ROUTING TO REMOTE HOSTS | |
2074 | ||
2075 | Q0301: What do \*lowest numbered MX record points to local host*\ and \*remote | |
2076 | host address is the local host*\ mean? | |
2077 | ||
2078 | A0301: They mean exactly what they say. Exim expected to route an address to a | |
2079 | remote host, but the IP address it obtained from a router was for the | |
2080 | local host. If you really do want to send over TCP/IP to the local host | |
2081 | (to a different version of Exim or another MTA, for example), see Q0206. | |
2082 | ||
2083 | More commonly, these errors arise when Exim thinks it is routing some | |
2084 | foreign domain. For example, the router configuration causes Exim to | |
2085 | look up the domain in the DNS, but when Exim examines the DNS output, | |
2086 | either the lowest numbered MX record points at the local host, or there | |
2087 | are no MX records, and the address record for the domain contains an | |
2088 | IP address that belongs to the local host. | |
2089 | ||
2090 | There has been a rash of instances of domains being deliberately set up | |
2091 | with MX records pointing to \"localhost"\ (or other names with A records | |
2092 | that specify 127.0.0.1), which causes this behaviour. You can use the | |
2093 | \ignore_target_hosts\ option to get Exim to ignore these records. The | |
2094 | default contiguration does this. For more discussion, see Q0319. For | |
2095 | other cases: | |
2096 | ||
2097 | (1) If the domain is meant to be handled as a local domain, there | |
2098 | is a problem with the configuration, because it should not then have | |
2099 | been looked up in the DNS. Check the \domains\ settings on your | |
2100 | routers. | |
2101 | ||
2102 | (2) If the domain is one for which the local host is providing a | |
2103 | relaying service (called ``mail hubbing''), possibly as part of a | |
2104 | firewall, you need to set up a router to tell Exim where to send | |
2105 | messages addressed to this domain, because the DNS directs them to | |
2106 | the local host. You should put a router like this one before the one | |
2107 | that does DNS lookups: | |
2108 | ||
2109 | ==> hubbed_hosts: | |
2110 | driver = manualroute | |
2111 | transport = remote_smtp | |
2112 | route_list = see discussion below | |
2113 | ||
2114 | The contents of the \route_list\ option depend on how many hosts you | |
2115 | are hubbing for, and how their names are related to the domain name. | |
2116 | Suppose the local host is a firewall, and all the domains in | |
2117 | \(*.foo.bar)\ have MX records pointing to it, and each domain | |
2118 | corresponds to a host of the same name. Then the setting could be | |
2119 | ||
2120 | ==> route_list = *.foo.bar $domain | |
2121 | ||
2122 | If there isn't a convenient relationship between the domain names | |
2123 | and the host names, you either have to list each domain separately, | |
2124 | or use a lookup expansion to look up the host from the domain, or | |
2125 | put the routing information in a file and use the \route_data\ | |
2126 | option with a lookup expansion. | |
2127 | ||
2128 | (3) If neither (1) nor (2) is the case, the lowest numbered MX record or | |
2129 | the address record for the domain should not be pointing to your | |
2130 | host. You should arrange to get the DNS mended. | |
2131 | ||
2132 | ||
2133 | Q0302: Why does Exim say \*all relevant MX records point to non-existent hosts*\ | |
2134 | when MX records point to IP addresses? | |
2135 | ||
2136 | A0302: MX records cannot point to IP addresses. They are defined to point to | |
2137 | host names, so Exim always interprets them that way. (An IP address is a | |
2138 | syntactically valid host name.) The DNS for the domain you are having | |
2139 | problems with is misconfigured. | |
2140 | ||
2141 | However, it appears that more and more DNS zones are breaking the rules | |
2142 | and putting IP addresses on the RHS of MX records. Exim follows the | |
2143 | rules and rejects this, but other MTAs do support it, so the | |
2144 | \allow_mx_to_ip\ was regretfully added at release 3.14 to permit this | |
2145 | heinous activity. | |
2146 | ||
2147 | ||
2148 | Q0303: How do I configure Exim to send all messages to a central server? I | |
2149 | don't want to do any local deliveries at all on this host. | |
2150 | ||
2151 | A0303: Use this as your first and only router: | |
2152 | ||
2153 | ==> send_to_gateway: | |
2154 | driver = manualroute | |
2155 | transport = remote_smtp | |
2156 | route_list = * central.server.host | |
2157 | ||
2158 | ||
2159 | Q0304: How do I configure Exim to send all non-local mail to a gateway host? | |
2160 | ||
2161 | A0304: Replace the \%dnslookup%\ router in the default configuration with the | |
2162 | following: | |
2163 | ||
2164 | ==> send_to_gateway: | |
2165 | driver = manualroute | |
2166 | domains = !+local_domains | |
2167 | transport = remote_smtp | |
2168 | route_list = * gate.way.host | |
2169 | ||
2170 | If there are several hosts you can send to, you can specify them as a | |
2171 | colon-separated list. | |
2172 | ||
2173 | ||
2174 | Q0305: How can I arrange for mail on my local network to be delivered directly | |
2175 | to the relevant hosts, but all other mail to be sent to my ISP's mail | |
2176 | server? The local hosts are all DNS-registered and behave like normal | |
2177 | Internet hosts. | |
2178 | ||
2179 | A0305: Set up a first router to pick off all the domains for your local | |
2180 | network. There are several ways you might do this. For example | |
2181 | ||
2182 | ==> local_network: | |
2183 | driver = dnslookup | |
2184 | transport = remote_smtp | |
2185 | domains = *.mydomain.com | |
2186 | ||
2187 | This does a perfectly conventional DNS routing operation, but only for | |
2188 | the domains that match \(*.mydomain.com)\. Follow this with a `smart | |
2189 | host' router: | |
2190 | ||
2191 | ==> internet: | |
2192 | driver = manualroute | |
2193 | domains = !+local_domains | |
2194 | transport = remote_smtp | |
2195 | route_list = * mail.isp.net | |
2196 | ||
2197 | This routes any other non-local domains to the smart host. | |
2198 | ||
2199 | ||
2200 | Q0306: How do I configure Exim to send all non-local mail to a central server | |
2201 | if it cannot be immediately delivered by my host? I don't want to have | |
2202 | queued mail waiting on my host. | |
2203 | ||
2204 | A0306: Add to the \%remote_smtp%\ transport the following: | |
2205 | ||
2206 | ==> fallback_hosts = central.server.name(s) | |
2207 | ||
2208 | If there are several names, they must be separated by colons. | |
2209 | ||
2210 | ||
2211 | Q0307: The \route_list\ setting \"^foo$:^bar$ $domain"\ in a \%manualroute%\ | |
2212 | router does not work. | |
2213 | ||
2214 | A0307: The first thing in a \route_list\ item is a single pattern, not a list of | |
2215 | patterns. You need to write that as \"^(foo|bar)$ $domain"\. | |
2216 | Alternatively, you could use several items and write | |
2217 | ||
2218 | ==> route_list = foo $domain; bar $domain | |
2219 | ||
2220 | Note the semicolon separator. This is because the second thing in each | |
2221 | item can itself be a list - of hosts. | |
2222 | ||
2223 | ||
2224 | Q0308: I have a domain for which some local parts must be delivered locally, | |
2225 | but the remainder are to be treated like any other remote addresses. | |
2226 | ||
2227 | A0308: One possible way of doing this is as follows: Assuming you are using a | |
2228 | configuration that is similar to the default one, first exclude your | |
2229 | domain from the first router by changing it to look like this: | |
2230 | ||
2231 | ==> non_special_remote: | |
2232 | driver = dnslookup | |
2233 | domains = ! +local_domains : ! special.domain | |
2234 | transport = remote_smtp | |
2235 | ignore_target_hosts = 127.0.0.0/8 | |
2236 | no_more | |
2237 | ||
2238 | Then add a second router which handles the local parts that are not to | |
2239 | be delivered locally: | |
2240 | ||
2241 | ==> special_remote: | |
2242 | driver = dnslookup | |
2243 | domains = special.domain | |
2244 | local_parts = ! lsearch;/list/of/special/localparts | |
2245 | transport = remote_smtp | |
2246 | ignore_target_hosts = 127.0.0.0/8 | |
2247 | no_more | |
2248 | ||
2249 | The remaining local parts will fall through to the remaining routers, | |
2250 | which can delivery them locally. | |
2251 | ||
2252 | ||
2253 | Q0309: How can I configure Exim on a firewall machine so that if mail arrives | |
2254 | addressed to a domain whose MX points to the firewall, it is forwarded | |
2255 | to the internal mail server, without having to have a list of all the | |
2256 | domains involved? | |
2257 | ||
2258 | A0309: As your first router, have the standard \%dnslookup%\ router from the | |
2259 | default configuration, with the added option | |
2260 | ||
2261 | ==> self = pass | |
2262 | ||
2263 | This will handle all domains whose lowest numbered MX records do not | |
2264 | point to your host. Because of the \no_more\ setting, if it encounters | |
2265 | an unknown domain, routing will fail. However, if it hits a domain whose | |
2266 | lowest numbered MX points to your host, the \self\ option comes into | |
2267 | play, and overrides \no_more\. The \"pass"\ setting causes it to pass | |
2268 | the address on to the next router. (The default causes it to generate an | |
2269 | error.) | |
2270 | ||
2271 | The only non-local domains that reach the second router are those with | |
2272 | MX records pointing to the local host. Set it up to send them to the | |
2273 | internal mail server like this: | |
2274 | ||
2275 | ==> internal: | |
2276 | driver = manualroute | |
2277 | domains = ! +local_domains | |
2278 | transport = remote_smtp | |
2279 | route_list = * internal.server | |
2280 | ||
2281 | ||
2282 | Q0310: If a DNS lookup returns no MX records why doesn't Exim just bin the | |
2283 | message? | |
2284 | ||
2285 | A0310: If a DNS lookup returns no MXs, Exim looks for an address record, in | |
2286 | accordance with the rules that are defined in the RFCs. If you want to | |
2287 | break the rules, you can set \mx_domains\ in the \%dnslookup%\ router, but | |
2288 | you will cut yourself off from those sites (and there still seem to be | |
2289 | plenty) who do not set up MX records. | |
2290 | ||
2291 | ||
2292 | Q0311: When a DNS lookup for MX records fails to complete, why doesn't Exim | |
2293 | send the messsage to the host defined by the A record? | |
2294 | ||
2295 | A0311: The RFCs are quite clear on this. Only if it is known that there are no | |
2296 | MX records is an MTA allowed to make use of the A record. When an MX | |
2297 | lookup fails to complete, Exim does not know whether there are any MX | |
2298 | records or not. There seem to be some name servers (or some | |
2299 | configurations of some name servers) that give a ``server fail'' error when | |
2300 | asked for a non-existent MX record. Exim uses standard resolver calls, | |
2301 | which unfortunately do not distinguish between this case and a timeout, | |
2302 | so all Exim can do is try again later. | |
2303 | ||
2304 | ||
2305 | Q0312: Is it possible to use a conditional expression for the host item in a | |
2306 | \route_list\ for \%manualroute%\ router? I tried the following, but it | |
2307 | doesn't work: | |
2308 | ||
2309 | ==> route_list = * ${if match{$header_from:}{\N.*\.usa\.net$\N} \ | |
2310 | {<smarthost1>}{<smarthost2>} | |
2311 | ||
2312 | A0312: The problem is that the second item in \route_list\ contains white | |
2313 | space, which means that it gets terminated prematurely. To avoid this, | |
2314 | you must put the second item in quotes: | |
2315 | ||
2316 | ==> route_list = * "${if match{$header_from:}{\N.*\.usa\.net$\N} \ | |
2317 | {<smarthost1>}{<smarthost2>}}" | |
2318 | ||
2319 | ||
2320 | Q0313: I send all external mail to a smart host, but this means that bad | |
2321 | addresses also get passed to the smart host. Can I avoid this? | |
2322 | ||
2323 | A0313: Assuming you have DNS availability, set up a conventional \%dnslookup%\ | |
2324 | router to do the routing, but in the \%remote_smtp%\ transport set this: | |
2325 | ||
2326 | ==> hosts = your.smart.host | |
2327 | hosts_override | |
2328 | ||
2329 | This will override the hosts that the router finds so that everything | |
2330 | goes to the smart host, but any non-existent domains will be failed by | |
2331 | the router. | |
2332 | ||
2333 | ||
2334 | Q0314: I have a really annoying intermittent problem where attempts to mail to | |
2335 | valid sites are rejected with \*unknown mail domain*\. This only happens a | |
2336 | few times a day and there is no particular pattern to the sites it | |
2337 | rejects. If I try to lookup the same domain a few minutes later then it | |
2338 | is OK. | |
2339 | ||
2340 | A0314: This is almost certainly a problem with the DNS resolver or the the | |
2341 | domain's name servers. | |
2342 | ||
2343 | (1) Have you linked Exim against the newest DNS resolver library that | |
2344 | comes with Bind? If you are using SunOS4 that may be your problem, as | |
2345 | the resolver that comes with that OS is known to be buggy and to give | |
2346 | intermittent false negatives. | |
2347 | ||
2348 | (2) Effects like this are sometimes seen if a domain's name servers get | |
2349 | out of step with each other. | |
2350 | ||
2351 | ||
2352 | Q0315: I'd like route all mail with addresses that can't be resolved (the DNS | |
2353 | lookup times out) to a relay machine. | |
2354 | ||
2355 | A0315: Set \pass_on_timeout\ on your \%dnslookup%\ router, and add below it a | |
2356 | \%manualroute%\ router that routes all relevant domains to the relay. | |
2357 | ||
2358 | ||
2359 | Q0316: I would like to forward all incoming email for a particular domain to | |
2360 | another host via SMTP. Whereabouts would I configure that? | |
2361 | ||
2362 | A0316: Use this as your first router: | |
2363 | ||
2364 | ==> special: | |
2365 | driver = manualroute | |
2366 | transport = remote_smtp | |
2367 | route_list = the.particular.domain the.other.host | |
2368 | ||
2369 | You will also need to adjust the ACL for incoming SMTP so that this | |
2370 | domain is accepted for relaying. If you are using the default | |
2371 | configuration, there is a domain list called \relay_domains\ that is | |
2372 | set up for this. | |
2373 | ||
2374 | ||
2375 | Q0317: What I'd like to do is have alternative smart hosts, where the one to be | |
2376 | used is determined by which ISP I'm connected to. | |
2377 | ||
2378 | A0317: The simplest way to do this is to arrange for the name of the smart host | |
2379 | du jour to be placed in a file when you connect, say \(/etc/smarthost)\. | |
2380 | Then you can read this file from a \%manualroute%\ router like this: | |
2381 | ||
2382 | ==> smarthost: | |
2383 | driver = manualroute | |
2384 | transport = remote_smtp | |
2385 | route_list = * ${readfile{/etc/smarthost}{}} | |
2386 | ||
2387 | The second argument of the \"readfile"\ item is a string that replaces | |
2388 | any newline characters in the file (in this case, with nothing). | |
2389 | By keeping the data out of the main configuration file, you avoid having | |
2390 | to HUP the daemon when it changes. | |
2391 | ||
2392 | ||
2393 | Q0318: Exim won't route to a host with no MX record. | |
2394 | ||
2395 | A0318: More than one thing may cause this. | |
2396 | ||
2397 | (1) Are you sure there really is no MX record? Sometimes a typo results | |
2398 | in a malformed MX record in the zone file, in which case some name | |
2399 | servers give a SERVFAIL error rather than NXDOMAIN. Exim has to treat | |
2400 | this as a temporary error, so it can't go on to look for address records. | |
2401 | You can check for this state using one of the DNS interrogation commands, | |
2402 | such as \(nslookup)\, \(host)\, or \(dig)\. | |
2403 | ||
2404 | (2) Is there a wildcard MX record for \(your)\ domain? Is the | |
2405 | \search_parents\ option on in your \%dnslookup%\ router? If the answer to | |
2406 | both these questions is ``yes'', that is the cause of the problem. When | |
2407 | the DNS resolver fails to find the MX record, it tries adding on your | |
2408 | domain if \search_parents\ is true, and thereby finds your wildcard MX | |
2409 | record. For example: | |
2410 | ||
2411 | . There is a wildcard MX record for \(*.a.b.c)\. | |
2412 | ||
2413 | . There is a host called \(x.y.z)\ that has an A record and no MX record. | |
2414 | ||
2415 | . Somebody on the host \(m.a.b.c)\ domain tries to mail to \(user@x.y.z)\. | |
2416 | ||
2417 | . Exim calls the DNS to look for an MX record for \(x.y.z)\. | |
2418 | ||
2419 | . The DNS doesn't find any MX record. Because \search_parents\ is true, | |
2420 | it then tries searching the current host's parent domain, so it | |
2421 | looks for \(x.y.z.a.b.c)\ and picks up the wildcard MX record. | |
2422 | ||
2423 | Setting \search_parents\ false makes this case work while retaining the | |
2424 | wildcard MX record. However, anybody on the host \(m.a.b.c)\ who mails to | |
2425 | \(user@n.a)\ (expecting it to go to \(user@n.a.b.c)\) now has a problem. The | |
2426 | \widen_domains\ option of the \%dnslookup%\ router may be helpful in this | |
2427 | circumstance. | |
2428 | ||
2429 | ||
2430 | Q0319: I have some mails on my queues that are sticking around longer than | |
2431 | the retry time indicates they should. They are all getting frozen | |
2432 | because some remote admin has set their MX record to 127.0.0.1. | |
2433 | ||
2434 | A0319: The admin in question is an idiot. Exim will always freeze such messages | |
2435 | because they are apparently routed to the local host. To bounce these | |
2436 | messages immediately, set | |
2437 | ||
2438 | ==> ignore_target_hosts = 127.0.0.1 | |
2439 | ||
2440 | on the \%dnslookup%\ router. This causes Exim to completely ignore any hosts | |
2441 | with that IP address. In fact, there are quite a number of IP addresses | |
2442 | that should never be used. Here is a suggested configuration list for | |
2443 | the IPv4 ones: | |
2444 | ||
2445 | ==> # Don't allow domains whose single MX (or A) record is a | |
2446 | # "special-use IPv4 address", as listed in RFC 3330. | |
2447 | ignore_target_hosts = \ | |
2448 | # Hosts on "this network"; RFC 1700 (page 4) states that these | |
2449 | # are only allowed as source addresses | |
2450 | 0.0.0.0/8 : \ | |
2451 | # Private networks, RFC 1918 | |
2452 | 10.0.0.0/8 : 172.16.0.0/12 : 192.168.0.0/16 : \ | |
2453 | # Internet host loopback address, RFC 1700 (page 5) | |
2454 | 127.0.0.0/8 : \ | |
2455 | # "Link local" block | |
2456 | 169.254.0.0/16 : \ | |
2457 | # "TEST-NET" - should not appear on the public Internet | |
2458 | 192.0.2.0/24 : \ | |
2459 | # 6to4 relay anycast addresses, RFC 3068 | |
2460 | 192.88.99.0/24 : \ | |
2461 | # Network interconnect device benchmark testing, RFC 2544 | |
2462 | 198.18.0.0/15 : \ | |
2463 | # Multicast addresses, RFC 3171 | |
2464 | 224.0.0.0/4 : \ | |
2465 | # Reserved for future use, RFC 1700 (page 4) | |
2466 | 240.0.0.0/4 | |
2467 | ||
2468 | ||
2469 | Q0320: How can I arrange for all mail to \*user@some.domain*\ to be forwarded | |
2470 | to \*user@other.domain*\? | |
2471 | ||
2472 | A0320: Put this as your first router: | |
2473 | ||
2474 | ==> forward: | |
2475 | driver = redirect | |
2476 | domains = some.domain | |
2477 | data = ${quote:$local_part}@other.domain | |
2478 | ||
2479 | ||
2480 | Q0321: How can I tell an Exim router to use only IPv4 or only IPv6 addresses | |
2481 | when it finds both types in the DNS? | |
2482 | ||
2483 | A0321: You can do this by making it ignore the addresses you don't want. This | |
2484 | example ignores all IPv6 addresses and all IPv4 addresses in the 127 | |
2485 | network: | |
2486 | ||
2487 | ==> ignore_target_hosts = <; 0000::0000/0 ; 127.0.0.0/8 | |
2488 | ||
2489 | To ignore all IPv4 addresses, use | |
2490 | ||
2491 | ==> ignore_target_hosts = 0.0.0.0/0 | |
2492 | ||
2493 | See Q0319 for a general discussion of \ignore_target_hosts\. | |
2494 | ||
2495 | ||
2496 | Q0322: How can I reroute all messages bound for 192.168.10.0 and 10.0.0.0 to | |
2497 | a specific mail server? | |
2498 | ||
2499 | A0322: That is an odd requirement. However, there is an obscure feature in | |
2500 | Exim, originally implemented for packet radio people, that perhaps can | |
2501 | help. Check out the \translate_ip_address\ generic router option. | |
2502 | ||
2503 | ||
2504 | ||
2505 | 4. ROUTING FOR LOCAL DELIVERY | |
2506 | ||
2507 | Q0401: I need to have any mail for \(virt.dom.ain)\ that doesn't match one of the | |
2508 | aliases in \(/usr/lib/aliases.virt)\ delivered to a particular address, for | |
2509 | example, \(postmaster@virt.dom.ain)\. | |
2510 | ||
2511 | A0401: Adding an asterisk to a search type causes Exim to look up ``*'' when the | |
2512 | normal lookup fails. So if your aliasing router is something like this: | |
2513 | ||
2514 | ==> virtual: | |
2515 | driver = redirect | |
2516 | domains = virt.dom.ain | |
2517 | data = ${lookup{$local_part}lsearch{/usr/lib/aliases.virt}} | |
2518 | no_more | |
2519 | ||
2520 | you should change \"lsearch"\ to \"lsearch*"\, and put this in the alias | |
2521 | file: | |
2522 | ||
2523 | ==> *: postmaster@virt.dom.ain | |
2524 | ||
2525 | This solution has the feature that if there are several unknown | |
2526 | addresses in the same message, only one copy gets sent to the | |
2527 | postmaster, because of Exim's normal de-duplication rules. | |
2528 | ||
2529 | NOTE: This solution works only if there is also an entry for \(postmaster)\ | |
2530 | in the alias file, ultimately resolving to an address that is not in | |
2531 | \(virt.dom.ain)\. See also Q0434. | |
2532 | ||
2533 | ||
2534 | Q0402: How do I arrange for all incoming email for \(*@some.domain)\ to go into one | |
2535 | pop3 mail account? The customer doesn't want to add a list of specific | |
2536 | local parts to the system. | |
2537 | ||
2538 | A0402: Set up a special transport that writes to the mailbox like this: | |
2539 | ||
2540 | ==> special_transport: | |
2541 | driver = appendfile | |
2542 | file = /pop/mailbox | |
2543 | envelope_to_add | |
2544 | return_path_add | |
2545 | delivery_date_add | |
2546 | user = exim | |
2547 | ||
2548 | The file will be written as the user \"exim"\. Then arrange to route all | |
2549 | mail for that domain to that transport, with a router like this: | |
2550 | ||
2551 | ==> special_router: | |
2552 | driver = accept | |
2553 | domains = some.domain | |
2554 | transport = special_transport | |
2555 | ||
2556 | ||
2557 | Q0403: How do I configure Exim to send messages for unknown local users to a | |
2558 | central server? | |
2559 | ||
2560 | A0403: Assuming you are using something like the default configuration, where | |
2561 | local users are processed by the later routers, you should add the | |
2562 | following router at the end: | |
2563 | ||
2564 | ==> unknown: | |
2565 | driver = manualroute | |
2566 | transport = remote_smtp | |
2567 | route_list = * server.host.name | |
2568 | no_verify | |
2569 | ||
2570 | However, you should if possible try to verify that the user is known on | |
2571 | the central server before accepting the message in the first place. This | |
2572 | can be done by making use of Exim's ``call forward'' facility. | |
2573 | ||
2574 | ||
2575 | Q0404: How can I arrange for messages submitted by (for example) Majordomo to | |
2576 | be handled specially? | |
2577 | ||
2578 | A0404: You can use the \condition\ option on a router, with a setting such as | |
2579 | ||
2580 | ==> condition = ${if and {{eq {$sender_host_address}{}} \ | |
2581 | {eq {$sender_ident}{majordom}}} {yes}{no}} | |
2582 | ||
2583 | This first tests for a locally-submitted message, by ensuring there is | |
2584 | no sending host address, and then it checks the identity of the user | |
2585 | that ran the submitting process. | |
2586 | ||
2587 | ||
2588 | Q0405: On a host that accepts mail for several domains, do I have to use fully | |
2589 | qualified addresses in \(/etc/aliases)\ or do I have to set up an alias | |
2590 | file for each domain? | |
2591 | ||
2592 | A0405: You can do it either way. The default aliasing router contains this line: | |
2593 | ||
2594 | ==> data = ${lookup{$local_part}lsearch{/etc/aliases}} | |
2595 | ||
2596 | which is what does the actual lookup. To make it look up the complete | |
2597 | address instead of just the local part, use | |
2598 | ||
2599 | ==> data = ${lookup{$local_part@$domain}lsearch{/etc/aliases}} | |
2600 | ||
2601 | If you want to use a separate file for each domain, use | |
2602 | ||
2603 | ==> data = ${lookup{$local_part}lsearch{/etc/aliases/$domain}} | |
2604 | ||
2605 | ||
2606 | Q0406: Some of my users are using the \(.forward)\ to pipe to a shell command which | |
2607 | appends to the user's INBOX. How can I forbid this? | |
2608 | ||
2609 | A0406: If you allow your users to run shells in pipes, you cannot control which | |
2610 | commands they run or which files they write to. However, you should point | |
2611 | out to them that writing to an INBOX by arbitrary commands is not | |
2612 | interlocked with the MTA and MUAs, and is liable to mess up the contents | |
2613 | of the file. | |
2614 | ||
2615 | If a user simply wants to choose a specific file for the delivery of | |
2616 | messages, this can be done by putting a file name in a \(.forward)\ file | |
2617 | rather than using a pipe, or by using the \"save"\ command in an Exim | |
2618 | filter file. | |
2619 | ||
2620 | You can set \forbid_pipe\ on the router, but that will prevent them from | |
2621 | running any pipe commands at all. Alternatively, you can restrict which | |
2622 | commands they may run in their pipes by setting the \allow_commands\ | |
2623 | and/or \restrict_to_path\ options in the \%address_pipe%\ transport. | |
2624 | ||
2625 | ||
2626 | Q0407: How can I arrange for a default value when using a query-style lookup | |
2627 | such as LDAP or NIS+ to handle aliases? | |
2628 | ||
2629 | A0407: Use a second query in the failure part of the original lookup, like | |
2630 | this: | |
2631 | ||
2632 | ==> data = ${lookup ldap\ | |
2633 | {ldap://x.y.z/l=yvr?aliasaddress?sub?(&(mail=$local_part@$domain))}\ | |
2634 | {$value}\ | |
2635 | {\ | |
2636 | ${lookup ldap \ | |
2637 | {ldap://x.y.z/l=yvr?aliasaddress?sub?(&(mail=default@$domain))}}\ | |
2638 | }} | |
2639 | ||
2640 | Of course, if the default is a fixed value you can just include it | |
2641 | directly. | |
2642 | ||
2643 | ||
2644 | Q0408: If I don't fully qualify the addresses in a virtual domain's alias file | |
2645 | then mail to aliases which also match the local domain get delivered to | |
2646 | the local domain. | |
2647 | ||
2648 | A0408: Set the \qualify_preserve_domain\ option on the \%redirect%\ router. | |
2649 | ||
2650 | ||
2651 | Q0409: I want mail for any local part at certain virtual domains to go | |
2652 | to a single address for each domain. | |
2653 | ||
2654 | A0409: One way to to this is | |
2655 | ||
2656 | ==> virtual: | |
2657 | driver = redirect | |
2658 | data = ${lookup{$domain}lsearch{/etc/virtual}} | |
2659 | ||
2660 | The \(/etc/virtual)\ file contains a list of domains and the addresses to | |
2661 | which their mail should be sent. For example: | |
2662 | ||
2663 | ==> domain1: postmaster@some.where.else | |
2664 | domain2: joe@xyz.plc | |
2665 | ||
2666 | If the number of domains is large, using a DBM or cdb file would be more | |
2667 | efficient. If the lookup fails to find the domain in the file, the value | |
2668 | of the \data\ option is empty, causing the router to decline. | |
2669 | ||
2670 | ||
2671 | Q0410: How can I make Exim look in the alias NIS map instead of \(/etc/aliases)\? | |
2672 | ||
2673 | A0410: The default configuration does not use NIS (many hosts don't run it). | |
2674 | You need to change this line in the \%system_aliases%\ router: | |
2675 | ||
2676 | ==> data = ${lookup{$local_part}lsearch{/etc/aliases}} | |
2677 | ||
2678 | Change it to | |
2679 | ||
2680 | ==> data = ${lookup{$local_part}nis{mail.aliases}} | |
2681 | ||
2682 | If you want to use \(/etc/aliases)\ as well as NIS, put this router (with | |
2683 | a different name) before or after the default one, depending on which | |
2684 | data source you want to take precedence. | |
2685 | ||
2686 | ||
2687 | Q0411: Why will Exim deliver a message locally to any username that is longer | |
2688 | than 8 characters as long as the first 8 characters match one of the | |
2689 | local usernames? | |
2690 | ||
2691 | A0411: The problem is in your operating system. Exim just calls the \^^getpwnam()^^\ | |
2692 | function to test a local part for being a local login name. It does not | |
2693 | presume to guess the maximum length of user name for the underlying | |
2694 | operating system. Many operating systems correctly reject names that are | |
2695 | longer than the maximum length; yours is apparently deficient in this | |
2696 | regard. To cope with such systems, Exim has an option called | |
2697 | \max_user_name_length\ which you can set to the maximum allowed length. | |
2698 | ||
2699 | ||
2700 | Q0412: Why am I seeing the error \*bad mode (100664) for /home/test/.forward*\? | |
2701 | I've looked through the documentation but can't see anything to suggest | |
2702 | that Exim has to do anything other than read the \(.forward)\ file. | |
2703 | ||
2704 | A0412: For security, Exim checks for mode bits that shouldn't be set, by | |
2705 | default 022. You can change this by setting the \modemask\ option of the | |
2706 | \%redirect%\ router that is handling \(.forward)\ files. | |
2707 | ||
2708 | ||
2709 | Q0413: When a user's \(.forward)\ file is syntactially invalid, Exim defers | |
2710 | delivery of all messages to that user, which sometimes include the | |
2711 | user's own test messages. Can it be told to ignore the \(.forward)\ file | |
2712 | and/or inform the user of the error? | |
2713 | ||
2714 | A0413: Setting \skip_syntax_errors\ on the redirect router causes syntax | |
2715 | errors to be skipped. When dealing with users' \(.forward)\ files it is best | |
2716 | to combine this with a setting of \syntax_errors_to\ in order to send | |
2717 | a message about the error to the user. However, to avoid an infinite | |
2718 | cascade of messages, you have to be able to send to an address that | |
2719 | bypasses \(.forward)\ file processing. This can be done by including a | |
2720 | router like this one | |
2721 | ||
2722 | ==> real_localuser: | |
2723 | driver = accept | |
2724 | check_local_user | |
2725 | transport = local_delivery | |
2726 | prefix = real- | |
2727 | ||
2728 | before the \%redirect%\ router that handles \(.forward)\ files. This will | |
2729 | do an ordinary local delivery without \(.forward)\ processing, if the | |
2730 | local part is prefixed by \"real-"\. You can then set something like | |
2731 | the following options on the \%redirect%\ router: | |
2732 | ||
2733 | ==> skip_syntax_errors | |
2734 | syntax_errors_to = real-$local_part@$domain | |
2735 | syntax_errors_text = "\ | |
2736 | This is an automatically generated message. An error has been \ | |
2737 | found\nin your .forward file. Details of the error are reported \ | |
2738 | below. While\nthis error persists, messages addressed to you will \ | |
2739 | get delivered into\nyour normal mailbox and you will receive a \ | |
2740 | copy of this message for\neach one." | |
2741 | ||
2742 | A final tidying setting to go with this is a rewriting rule that changes | |
2743 | \"real-username"\ into just \"username"\ in the headers of the message: | |
2744 | ||
2745 | ==> \N^real-([^@]+)@your\.dom\.ain$\N $1@your.dom.ain h | |
2746 | ||
2747 | This means that users won't ever see the \"real-"\ prefix, unless they | |
2748 | look at the ::Envelope-To:: header. | |
2749 | ||
2750 | ||
2751 | Q0414: I have set \caseful_local_part\ on the routers that handle my local | |
2752 | domain because my users have upper case letters in their login names, | |
2753 | but incoming mail now has to use the correct case. Can I relax this | |
2754 | somehow? | |
2755 | ||
2756 | A0414: If you really have to live with caseful user names but want incoming | |
2757 | local parts to be caseless, then you have to maintain a file, indexed by | |
2758 | the lower case forms, that gives the correct case for each login, like | |
2759 | this: | |
2760 | ||
2761 | ==> admin: Admin | |
2762 | steven: Steven | |
2763 | mcdonald: McDonald | |
2764 | lamanch: LaManche | |
2765 | ... | |
2766 | ||
2767 | and at the start of the routers that handle your local domain, put one | |
2768 | like this: | |
2769 | ||
2770 | ==> set_case_router: | |
2771 | driver = redirect | |
2772 | data = ${lookup{${lc:$local_part}}lsearch{/the/file}} | |
2773 | qualify_preserve_domain | |
2774 | ||
2775 | For efficiency, you should also set the \redirect_router\ option to cause | |
2776 | processing of the changed address to begin at the next router. If you | |
2777 | are otherwise using the default configuration, the setting would be | |
2778 | ||
2779 | ==> redirect_router = system_aliases | |
2780 | ||
2781 | If there are lots of users, then a DBM or cdb file would be more | |
2782 | efficient than a linear search. If you are handling several domains, | |
2783 | you will have to extend this configuration to cope appropriately. | |
2784 | ||
2785 | ||
2786 | Q0415: Can I use my existing alias files and forward files as well as procmail | |
2787 | and effectively drop in Exim in place of Sendmail ? | |
2788 | ||
2789 | A0415: Yes, as long as your alias and forward files don't assume that pipes are | |
2790 | going to run under a shell. If they do, you either have to change them, | |
2791 | or configure Exim to use a shell (which it doesn't by default). | |
2792 | ||
2793 | ||
2794 | Q0416: What is quickest way to set up Exim so any message sent to a | |
2795 | non-existing user would bounce back with a different message, based | |
2796 | on the name of non-existing user? | |
2797 | ||
2798 | A0416: Place this router last, so that it catches any local addresses that | |
2799 | are not otherwise handled: | |
2800 | ||
2801 | ==> non_exist: | |
2802 | driver = accept | |
2803 | transport = non_exist_reply | |
2804 | no_verify | |
2805 | ||
2806 | Then add the following transport to the transports section: | |
2807 | ||
2808 | ==> non_exist_reply: | |
2809 | driver = autoreply | |
2810 | user = exim | |
2811 | to = $sender_address | |
2812 | subject = User does not exist | |
2813 | text = You sent mail to $local_part. That's not a valid user here. \ | |
2814 | The subject was: $subject. | |
2815 | ||
2816 | If you want to pick up a message from a file, you can use the \file\ | |
2817 | option (use \file_expand\ if you want its contents expanded). | |
2818 | ||
2819 | ||
2820 | Q0417: What do I need to do to make Exim handle \(/usr/ucb/vacation)\ processing | |
2821 | automatically, so that people could just create a \(.vacation.msg)\ file in | |
2822 | their home directory and not have to edit their \(.forward)\ file? | |
2823 | ||
2824 | A0417: Add a new router like this, immediately before the normal \%localuser%\ | |
2825 | router: | |
2826 | ||
2827 | ==> vacation: | |
2828 | driver = accept | |
2829 | check_local_user | |
2830 | require_files = $home/.vacation.msg | |
2831 | transport = vacation_transport | |
2832 | unseen | |
2833 | ||
2834 | and a matching new transport like this: | |
2835 | ||
2836 | ==> vacation_transport: | |
2837 | driver = pipe | |
2838 | command = /usr/ucb/vacation $local_part | |
2839 | ||
2840 | However, some versions of \(/usr/ucb/vacation)\ do not work properly unless | |
2841 | the DBM file(s) it uses are created in advance - it won't create them | |
2842 | itself. You also need a way of removing them when the vacation is over. | |
2843 | ||
2844 | Another possibility is to use a fixed filter file which is run whenever | |
2845 | \(.vacation.msg)\ exists, for example: | |
2846 | ||
2847 | ==> vacation: | |
2848 | driver = redirect | |
2849 | check_local_user | |
2850 | require_files = $home/.vacation.msg | |
2851 | file = /some/central/filter | |
2852 | allow_filter | |
2853 | ||
2854 | The filter file should use the \"if personal"\ check before sending mail, | |
2855 | to avoid generating automatic responses to mailing lists. If sending a | |
2856 | message is all that it does, this doesn't count as a ``significant'' | |
2857 | delivery, so the original message goes on to be delivered as normal. | |
2858 | ||
2859 | Yet another possibility is to make use of Exim's \%autoreply%\ transport, | |
2860 | and not use \(/usr/ucb/vacation)\ at all. | |
2861 | ||
2862 | ||
2863 | Q0418: I want to use a default entry in my alias file to handle unknown local | |
2864 | parts, but it picks up the local parts that the aliases generate. For | |
2865 | example, if the alias file is | |
2866 | ||
2867 | ==> luke.skywalker: luke | |
2868 | ls: luke | |
2869 | *: postmaster | |
2870 | ||
2871 | then messages addressed to \/luke.skywalker/\ end up at \/postmaster/\. | |
2872 | ||
2873 | A0418: The default mechanism works best with virtual domains, where the | |
2874 | generated address is not in the same domain. If you just want to pick up | |
2875 | all unknown local parts and send them to postmaster, an easier way to do | |
2876 | it is to put this as your last router: | |
2877 | ||
2878 | ==> unknown: | |
2879 | driver = redirect | |
2880 | data = postmaster | |
2881 | no_verify | |
2882 | ||
2883 | Another possibility is to put the redirect router for these aliases | |
2884 | after all the other routers, so that local parts which are user names | |
2885 | get picked off first. You will need to have two aliasing routers if | |
2886 | there are some local parts (e.g. \/root/\) which are login names, but which | |
2887 | you want to handle as aliases. | |
2888 | ||
2889 | ||
2890 | Q0419: I have some obsolete domains which people have been warned not to use | |
2891 | any more. How can I arrange to delete any mail that is sent to them? | |
2892 | ||
2893 | A0419: To reject them at SMTP time, with a customized error message, place | |
2894 | statments like this in the ACL: | |
2895 | ||
2896 | ==> deny message = The domain $domain is obsolete | |
2897 | domains = lsearch;/etc/exim/obsolete.domains | |
2898 | ||
2899 | For messages that don't arrive over SMTP, you can use a router like | |
2900 | this to bounce them: | |
2901 | ||
2902 | ==> obsolete: | |
2903 | driver = redirect | |
2904 | domains = lsearch;/etc/exim/obsolete.domains | |
2905 | allow_fail | |
2906 | data = :fail: the domain $domain is obsolete | |
2907 | ||
2908 | If you just want to throw away mail to those domains, accept them at | |
2909 | SMTP time, and use a router like this: | |
2910 | ||
2911 | ==> obsolete: | |
2912 | domains = lsearch;/etc/exim/obsolete.domains | |
2913 | data = :blackhole: | |
2914 | ||
2915 | ||
2916 | Q0420: How can I arrange that mail addressed to \(anything@something.mydomain.com)\ | |
2917 | gets delivered to \(something@mydomain.com)\? | |
2918 | ||
2919 | A0420: Set up a router like this: | |
2920 | ||
2921 | ==> user_from_domain: | |
2922 | driver = redirect | |
2923 | data = ${if match{$domain}{\N^(.+)\.mydomain\.com$\N}\ | |
2924 | {$1@mydomain.com}} | |
2925 | ||
2926 | ||
2927 | Q0421: I can't get a regular expression to work in a \local_parts\ option on | |
2928 | one of my routers. | |
2929 | ||
2930 | A0421: Have you remembered to protect any backslash and dollar characters in | |
2931 | your regex from unwanted expansion? The easiest way is to use the | |
2932 | \"@\N"\ facility, like this: | |
2933 | ||
2934 | ==> local_parts = \N^0740\d{6}\N | |
2935 | ||
2936 | ||
2937 | Q0422: How can I arrange for all addresses in a group of domains \(*.example.com)\ | |
2938 | to share the same alias file? I have a number of such groups. | |
2939 | ||
2940 | A0422: For a single group you could just hard wire the file name into a router | |
2941 | that had | |
2942 | ||
2943 | ==> domains = *.example.com | |
2944 | ||
2945 | set, to restrict it to the relevant domains. For a number of such groups | |
2946 | you can create a file containing the domains, like this: | |
2947 | ||
2948 | ==> *.example1.com example1.com | |
2949 | *.example2.com example2.com | |
2950 | ... | |
2951 | ||
2952 | Then create a router like this | |
2953 | ||
2954 | ==> domain_aliases: | |
2955 | driver = redirect | |
2956 | domains = partial-lsearch;/that/file | |
2957 | data = ${lookup{$local_part}lsearch*{/etc/aliases.d/$domain_data}} | |
2958 | ||
2959 | The variable \$domain_data$\ contains the data that was looked up when the | |
2960 | \domains\ option was matched, i.e. \"example1.com"\, \"example2.com"\, etc. | |
2961 | in this case. | |
2962 | ||
2963 | ||
2964 | Q0423: Some of our users have no home directories; the field in the password | |
2965 | file contains \(/no/home/dir)\. This causes the error \*failed to stat | |
2966 | /no/home/dir (No such file or directory)*\ when Exim tries to look for a | |
2967 | \(.forward file)\, and the delivery is deferred. | |
2968 | ||
2969 | A0423: There are two issues involved here: | |
2970 | ||
2971 | (1) With the default configuration, you are asking Exim to check for a | |
2972 | \(.forward)\ file in the user's home directory. If no file is found, | |
2973 | Exim tries to \^^stat()^^\ the home directory. This is so that it will | |
2974 | notice a missing NFS home directory, and not treat it as if the | |
2975 | \(.forward)\ file did not exist. This \^^stat()^^\ is failing when the | |
2976 | home directory really doesn't exist. You should arrange for the | |
2977 | \%userforward%\ router not to run for these special users, by adding | |
2978 | this line: | |
2979 | ||
2980 | ==> condition = ${if eq {$home}{/no/home/dir}{no}{yes}} | |
2981 | ||
2982 | (2) If you use \check_local_user\ on another router to route to a local | |
2983 | transport (again, this is what is in the default configuration), you | |
2984 | will also have to specify a current directory for the transport, because | |
2985 | by default it makes the home directory current. This is easily done by | |
2986 | adding | |
2987 | ||
2988 | ==> current_directory = / | |
2989 | ||
2990 | to the transport or | |
2991 | ||
2992 | ==> transport_current_directory = / | |
2993 | ||
2994 | to the router. Or you can add \home_directory\ to the transport, because | |
2995 | the current directory defaults to the home directory. | |
2996 | ||
2997 | ||
2998 | Q0424: How can I disable Exim's de-duplication features? I want it to do two | |
2999 | deliveries if two different aliases expand to the same address. | |
3000 | ||
3001 | A0424: This is not possible. Duplication has other ramifications other than | |
3002 | just (in)convenience. Consider: | |
3003 | ||
3004 | . Message is addressed to A and to B. | |
3005 | ||
3006 | . Both A and B are aliased to C. | |
3007 | ||
3008 | . Without de-duplication, two deliveries to C are scheduled. | |
3009 | ||
3010 | . One delivery happens, Exim records that it has delivered the message | |
3011 | to C. | |
3012 | ||
3013 | . The next delivery fails (C's mailbox is over quota, say). | |
3014 | ||
3015 | Next time round, Exim wants to know if it has already delivered to C or | |
3016 | not, before scheduling a new delivery. Has it? Obviously, if duplicate | |
3017 | deliveries are supported, it has to remember not only that it has | |
3018 | delivered to C but also the ``history'' of how that delivery happened - in | |
3019 | effect an ancestry list back to the original envelope address. This it | |
3020 | does not do, and changing it to work in that way would be a lot of work | |
3021 | and a big upheaval. | |
3022 | ||
3023 | The best way to get duplicate deliveries if you want them is not to use | |
3024 | aliases, but to route the addresses directly to a transport, e.g. | |
3025 | ||
3026 | ==> duplicates: | |
3027 | driver = accept | |
3028 | local_parts = lsearch;/etc/list/of/special/local/parts | |
3029 | transport = local_delivery | |
3030 | user = exim | |
3031 | ||
3032 | ||
3033 | Q0425: My users' mailboxes are distributed between several servers according to | |
3034 | the first letter of the user name. All the servers receive incoming mail | |
3035 | at random. I would like to have the same configuration file for all the | |
3036 | servers, which does local delivery for the mailboxes it holds, and sends | |
3037 | other addresses to the correct other server. Is this possible? | |
3038 | ||
3039 | A0425: It is easiest if you arrange for all the users to have password entries | |
3040 | on all the servers. This means that non-existent users can be detected | |
3041 | at the first server they reach. Set up a file containing a mapping from | |
3042 | the first letter of the user names to the servers where their mailboxes | |
3043 | are held. For example: | |
3044 | ||
3045 | ==> a: server1 | |
3046 | b: server1 | |
3047 | c: server2 | |
3048 | ... | |
3049 | ||
3050 | Before the normal \%localuser%\ router, place the following router: | |
3051 | ||
3052 | ==> mailbox_host: | |
3053 | driver = manualroute | |
3054 | check_local_user | |
3055 | transport = remote_smtp | |
3056 | route_list = * ${lookup{${substr_0_1:$local_part}}lsearch{/etc/mapfile}} | |
3057 | self = pass | |
3058 | ||
3059 | This router checks for a local account, then looks up the host from the | |
3060 | first character of the local part. If the host is not the local host, | |
3061 | the address is routed to the \%remote_smtp%\ transport, and sent to the | |
3062 | correct host. If the host is the local host, the \self\ option causes | |
3063 | the router to pass the address to the next router, which does a local | |
3064 | delivery. | |
3065 | ||
3066 | The router is skipped for local parts that are not the names of local | |
3067 | users, and so these addresses fail. | |
3068 | ||
3069 | ||
3070 | Q0426: One of the things I want to set up is for \(anything@onedomain)\ to forward | |
3071 | to \(anything@anotherdomain)\. I tried adding \($local_part@anotherdomain)\ to | |
3072 | my aliases but it did not expand - it sent it to that literal address. | |
3073 | ||
3074 | A0426: If you want to do it that way, you can use the \"expand"\ operator on | |
3075 | the lookup used in the data option of the redirect router. For example: | |
3076 | ||
3077 | ==> data = ${expand:${lookup{$local_part}lsearch*{/etc/aliases}}} | |
3078 | ||
3079 | Another approach is to use a router like this: | |
3080 | ||
3081 | ==> forwarddomain: | |
3082 | driver = redirect | |
3083 | domains = onedomain | |
3084 | data = $local_part@anotherdomain | |
3085 | ||
3086 | The value of \data\ can, of course, be more complicated, involving | |
3087 | lookups etc. if you have lots of different cases. | |
3088 | ||
3089 | ||
3090 | Q0427: How can I have an address looked up in two different alias files, and | |
3091 | delivered to all the addresses that are found? | |
3092 | ||
3093 | A0427: Use a router like this: | |
3094 | ||
3095 | ==> multi_aliases: | |
3096 | driver = redirect | |
3097 | data = ${lookup{$local_part}lsearch{/etc/aliases1}\ | |
3098 | {$value${lookup{$local_part}lsearch{/etc/aliases2}{,$value}}}\ | |
3099 | {${lookup{$local_part}lsearch{/etc/aliases2}{$value}fail}}}\ | |
3100 | ||
3101 | If the first lookup succeeds, the result is its data, followed by the | |
3102 | data from the second lookup, if any, separated by a comma. If the first | |
3103 | lookup fails, the result is the data from the third lookup (which also | |
3104 | looks in the second file), but if this also fails, the entire expansion | |
3105 | is forced to fail, thereby causing the router to decline. | |
3106 | ||
3107 | Another approach is to use two routers, with the first re-generating the | |
3108 | original local part when it succeeds. This won't get processed by the | |
3109 | same router again. For example: | |
3110 | ||
3111 | ==> multi_aliases1: | |
3112 | driver = redirect | |
3113 | data = ${lookup{$local_part}lsearch{/etc/aliases1}{$value,$local_part}} | |
3114 | ||
3115 | ==> multi_aliases2: | |
3116 | data = ${lookup{$local_part}lsearch{/etc/aliases2}} | |
3117 | ||
3118 | This scales more easily to three or more alias files. | |
3119 | ||
3120 | ||
3121 | Q0428: I've converted from Sendmail, and I notice that Exim doesn't make use | |
3122 | of the \"owner-"\ entries in my alias file to change the sender address in | |
3123 | outgoing messages to a mailing list. | |
3124 | ||
3125 | A0428: If you have an alias file with entries like this: | |
3126 | ||
3127 | ==> somelist: a@b, c@d, ... | |
3128 | owner-somelist: postmaster | |
3129 | ||
3130 | Sendmail assumes that the second entry specifies a new sender address | |
3131 | for the first. Exim does not make this assumption. However, you can make | |
3132 | it take the same action, by adding | |
3133 | ||
3134 | ==> errors_to = owner-$local_part@whatever.domain | |
3135 | ||
3136 | to the configuration for your aliasing router. This is fail-safe, | |
3137 | because Exim verifies a new sender address before using it. Thus, the | |
3138 | change of sender address occurs only when the owner entry exists. | |
3139 | ||
3140 | ||
3141 | Q0429: I would like to deliver mail addressed to a given domain to local | |
3142 | mailboxes, but also to generate messages to the envelope senders. | |
3143 | ||
3144 | A0429: You can do this with an ``unseen'' router and an \%autoreply%\ transport, | |
3145 | along the following lines: | |
3146 | ||
3147 | ==> # Router | |
3148 | auto_warning_r: | |
3149 | driver = accept | |
3150 | check_local_user | |
3151 | domains = <domains you want to do this for> | |
3152 | condition = ${if eq{$sender_address}{}{no}{yes}} | |
3153 | transport = warning_t | |
3154 | no_verify | |
3155 | unseen | |
3156 | ||
3157 | Place this router immediately before the normal \%localuser%\ router. The | |
3158 | \unseen\ option means that the address is still passed on to the next | |
3159 | router. The transport is configured like this: | |
3160 | ||
3161 | ==> # Transport | |
3162 | warning_t: | |
3163 | driver = autoreply | |
3164 | file = /usr/local/mail/warning.txt | |
3165 | file_expand | |
3166 | from = postmaster@your.domain | |
3167 | to = $sender_address | |
3168 | user = exim | |
3169 | subject = Re: Your mail to $local_part@$domain | |
3170 | ||
3171 | Note the use of the \condition\ option to avoid attempting to send a | |
3172 | message when there is no sender (that is, when the incoming message is a | |
3173 | bounce message). You can of course extend this to include other | |
3174 | conditions. If you want to log the sending of messages, you can add | |
3175 | ||
3176 | ==> log = /some/file | |
3177 | ||
3178 | to the transport and also make use of the \once\ option if you want to | |
3179 | send only one message to each sender. | |
3180 | ||
3181 | ||
3182 | Q0430: Whenever Exim tries to route a local address, it gives a permission | |
3183 | denied error for the \(.forward)\ file, like this: | |
3184 | ||
3185 | ==> 1998-08-10 16:55:32 0z5y2W-0000B8-00 == xxxx@yyy.zzz <xxxx@yyy.zz> | |
3186 | D=userforward defer (-1): failed to open /home/xxxx/.forward | |
3187 | (userforward router): Permission denied (euid=1234 egid=101) | |
3188 | ||
3189 | A0430: Have you remembered to make Exim setuid \/root/\? | |
3190 | ||
3191 | ||
3192 | Q0431: How do I configure Exim to allow arbitrary extensions in local parts, of | |
3193 | the form \/+extension/\? | |
3194 | ||
3195 | A0431: Add this pre-condition to the relevant router: | |
3196 | ||
3197 | ==> local_part_suffix = +* | |
3198 | ||
3199 | If you want the extensions to be optional, also add the option | |
3200 | ||
3201 | ==> local_part_suffix_optional | |
3202 | ||
3203 | When the router runs, \$local_part$\ contains the local part with the | |
3204 | extension removed, and the extension (if any) is in \$local_part_suffix$\. | |
3205 | If you have set \check_local_user\, the test is carried out after the | |
3206 | extension is removed. | |
3207 | ||
3208 | ||
3209 | Q0432: I use NIS for my user data. How can I stop Exim rejecting mail when my | |
3210 | NIS servers are being restarted? | |
3211 | ||
3212 | A0432: Exim doesn't know that you are using NIS; it just calls the \^^getpwnam()^^\ | |
3213 | function, which is routed by nsswitch. Unfortunately, \^^getpwnam()^^\ | |
3214 | was never designed to be routed through NIS, and it returns NULL if the | |
3215 | entry is not found or if the connection to the NIS server fails. This | |
3216 | means that Exim cannot tell the difference between ``no such user'' and | |
3217 | ``NIS is down''. | |
3218 | ||
3219 | Crutches to help with this problem are \finduser_retries\ in Exim, and | |
3220 | \^nscd^\ on the Unix side, but they are not perfect, and mail can still | |
3221 | be lost. However, Nico Erfurth pointed out that you can create a router | |
3222 | for Exim that tests for the availability of NIS, and force a defer if | |
3223 | NIS is not running: | |
3224 | ||
3225 | ==> check_nis: | |
3226 | driver = redirect | |
3227 | data = ${lookup {$local_part} nis {passwd}{}} | |
3228 | ||
3229 | This should be placed before any router that makes any use of NIS, | |
3230 | typically at the start of your local routers. How does it work? If | |
3231 | your NIS server is reachable, the lookup will take place, and whether it | |
3232 | succeeds or fails, the result is an empty strting. This causes the | |
3233 | router to decline, and the address is passed to the following routers. | |
3234 | If your NIS server is down, the lookup defers, and this causes the | |
3235 | router to defer. A verification of an incoming address gets a temporary | |
3236 | rejection, and a delivery is deferred till later. | |
3237 | ||
3238 | ||
3239 | Q0433: How can I arrange for a single address to be processed by \*both*\ | |
3240 | \%redirect%\ \*and*\ \%accept%\? | |
3241 | ||
3242 | A0433: Check out the \unseen\ option. | |
3243 | ||
3244 | ||
3245 | Q0434: How can I redirect all local parts that are not in my system aliases to | |
3246 | a single address? I tried using an asterisk in the system alias file | |
3247 | with an \"lsearch*"\ lookup, but that send \*all*\ messages to the | |
3248 | default address. | |
3249 | ||
3250 | A0434: If your alias file generates addresses in the local domain, they are | |
3251 | also processed as a potential aliases. For example, suppose this is your | |
3252 | alias file: | |
3253 | ||
3254 | ==> caesar: jc | |
3255 | anthony: ma | |
3256 | *: brutus | |
3257 | ||
3258 | The local part \/caesar/\ is aliased to \/jc/\, but that address is then | |
3259 | reprocessed by the routers. As the address is in the local domain, the | |
3260 | alias file is again consulted, and this time the default matches. In | |
3261 | fact after the second aliasing, \/brutus/\ is also processed again from | |
3262 | the start, and is aliased to itself. However, this happens only once, | |
3263 | because the next time, Exim notices that the aliasing router has already | |
3264 | processed \/brutus/\, so the router is skipped in order to avoid | |
3265 | looping. | |
3266 | ||
3267 | There are several ways of solving this problem; which one you use | |
3268 | depends on your aliasing data. | |
3269 | ||
3270 | (1) If the result of aliasing is always a local user name, that is, | |
3271 | aliasing never generates another alias, you can use the | |
3272 | \redirect_router\ option on the router to specify that processing | |
3273 | the generated addresses must start at the next router. For example: | |
3274 | ||
3275 | ==> redirect_router = userforward | |
3276 | ||
3277 | assuming that the next router is called \%userforward%\. This | |
3278 | ensures that there is at most one pass through the aliasing router. | |
3279 | ||
3280 | (2) If you cannot rely on aliases generating non-aliases, it is often | |
3281 | easier not to use a default alias, but instead to place a router | |
3282 | such as the one below after all the other local routers (for the | |
3283 | relevant domains): | |
3284 | ||
3285 | ==> catch_unknown: | |
3286 | driver = redirect | |
3287 | domains = ... | |
3288 | data = brutus@$domain | |
3289 | ||
3290 | Note that the default aliasing technique works more successfully for | |
3291 | virtual domains (see Q0401) because the generated address for the | |
3292 | default is not usually in the same virtual domain as the incoming | |
3293 | address. | |
3294 | ||
3295 | ||
3296 | Q0435: My alias file contains fully qualified addresses as keys, and some | |
3297 | wildcard domains in the form @foo.bar. Can Exim handle these? | |
3298 | ||
3299 | A0435: You can handle fully qualified addresses with this router: | |
3300 | ||
3301 | ==> qualified_aliases: | |
3302 | driver = redirect | |
3303 | data = ${lookup{$local_part@$domain}lsearch{/etc/aliases}} | |
3304 | ||
3305 | (Add any other options you need for the \%redirect%\ router.) Place this | |
3306 | router either before or after the default aliases router that looks up | |
3307 | the local part only. (Or, if you have no unqualified aliases, replace | |
3308 | the default router.) | |
3309 | ||
3310 | To handle wildcards in the form @foo.bar you will need yet another | |
3311 | router. (Wildcards of the form *@foo.bar can be handled by an lsearch*@ | |
3312 | lookup.) Something like this: | |
3313 | ||
3314 | ==> wildcard_aliases: | |
3315 | driver = redirect | |
3316 | data = ${lookup{@$domain}lsearch{/etc/aliases}} | |
3317 | ||
3318 | Place this after the routers that handle the more specific aliases. | |
3319 | ||
3320 | ||
3321 | ||
3322 | 5. FILTERING | |
3323 | ||
3324 | Q0501: My filter isn't working. How can I test it? | |
3325 | ||
3326 | A0501: Use the \-bf-\ option (\-bF-\ for a system filter) to test the basic operation | |
3327 | of your filter. You can request debugging information for filtering only | |
3328 | by adding \"-d-all+filter"\ to the command. | |
3329 | ||
3330 | ||
3331 | Q0502: What I really need is the ability to obtain the result of a pipe | |
3332 | command so that I can filter externally and redirect internally. Is | |
3333 | this possible? | |
3334 | ||
3335 | A0502: The result of a pipe command is not available to a filter, because Exim | |
3336 | does not run any actual deliveries while filtering. It just sets up | |
3337 | deliveries at this time. They all actually happen later. If you want to | |
3338 | run pipes and examine their results, you need to set up a single | |
3339 | delivery to a delivery agent such as \^procmail^\ which provides this kind | |
3340 | of facility. | |
3341 | ||
3342 | An possible alternative is to use the \"${run"\ expansion item to run an | |
3343 | external command while filtering. In this case, you can make use of some | |
3344 | of the results of the command. | |
3345 | ||
3346 | ||
3347 | Q0503: I received a message with a ::Subject:: line that contained a non-printing | |
3348 | character (a carriage return). This messed up my filter file. Is there a | |
3349 | way to get round it? | |
3350 | ||
3351 | A0503: Instead of \"$h_subject:"\ use \"${escape:$h_subject:}"\ | |
3352 | ||
3353 | ||
3354 | Q0504: I want to search for \"$"\ in the subject line, but I can't seem to get | |
3355 | the syntax. | |
3356 | ||
3357 | A0504: Try one of these: | |
3358 | ||
3359 | ==> if $h_subject: contains \$ then ... | |
3360 | if $h_subject: contains "\\$" then ... | |
3361 | ||
3362 | ||
3363 | Q0505: My problem is that Exim replaces \$local_part$\ with an empty string in the | |
3364 | system filtering. What's wrong or what did I miss? | |
3365 | ||
3366 | A0505: A message may have many recipients. The system filter is run just once | |
3367 | at the start of a delivery attempt. Consequently, it does not make sense | |
3368 | to set \$local_part$\. Which recipient should it be set to? However, you | |
3369 | can access all the recipients from a system filter via the variable | |
3370 | called \$recipients$\. | |
3371 | ||
3372 | ||
3373 | Q0506: Using \$recipients$\ in a system filter gives me another problem: how can | |
3374 | I do a string lookup if \$recipients$\ is a list of addresses? | |
3375 | ||
3376 | A0506: Check out the section of the filter specification called \*Testing a list of | |
3377 | addresses*\. If that doesn't help, you may have to resort to calling an | |
3378 | embedded Perl interpreter - but that is expensive. | |
3379 | ||
3380 | ||
3381 | Q0507: What are the main differences between using an Exim filter and using | |
3382 | \^procmail^\? | |
3383 | ||
3384 | A0507: Exim filters and \^procmail^\ provide different facilities. Exim filters run | |
3385 | at routing time, before any deliveries are done. A filter is like a | |
3386 | ``\(.forward)\ file with conditions''. One of the benefits is de-duplication. | |
3387 | Another is that if you forward, you are forwarding the original message. | |
3388 | ||
3389 | However, this does mean that pipes etc. are not run at filtering time, | |
3390 | nor can you change the headers, because the message may have other | |
3391 | recipients and Exim keeps only a single set of headers. | |
3392 | ||
3393 | \^procmail^\ runs at delivery time. This is for one recipient only, and so | |
3394 | it can change headers, run pipes and check the results, etc. However, if | |
3395 | it wants to forward, it has to create a new message containing a copy | |
3396 | of the original message. | |
3397 | ||
3398 | It's your choice as to which of these you use. You can of course use | |
3399 | both. | |
3400 | ||
3401 | ||
3402 | Q0508: How can I allow the use of relative paths in users' filter files when | |
3403 | the directories concerned are not available from the password data? | |
3404 | ||
3405 | A0508: You need to be running Exim 4.11 or later. You can then specify a value | |
3406 | for \$home$\ by setting the router_home_directory option on the | |
3407 | \%redirect%\ router. | |
3408 | ||
3409 | For earlier releases, there is no way to specify the value of \$home$\ | |
3410 | for a \%redirect%\ router; it either comes from the password data as a | |
3411 | result of \check_local_user\, or is unset. | |
3412 | ||
3413 | ||
3414 | Q0509: How can I set up a filter file to detect and block virus attachments? | |
3415 | ||
3416 | A0509: Exim's filter facilities aren't powerful enough to do much more than | |
3417 | very crude testing. Most people that want virus checking are nowadays | |
3418 | using one of the separate scanning programs such as \^exiscan^\ (see | |
3419 | \?http://duncanthrax.net/exiscan/?\). There is some further information | |
3420 | about scanning with Exim via \?http://www.timj.co.uk/linux/exim.php?\. | |
3421 | ||
3422 | ||
3423 | Q0510: Is it possible to write code for scanning messages in Python? | |
3424 | ||
3425 | A0510: \^elspy^\ is a layer of glue code that enables you to write Python code | |
3426 | to scan email messages at SMTP time. \^elspy^\ also includes a small | |
3427 | Python library with common mail-scanning tools, including an interface | |
3428 | to SpamAssassin and a simple but effective virus detector. You can | |
3429 | optain \^elspy^\ from \?http://elspy.sourceforge.net/?\. | |
3430 | ||
3431 | ||
3432 | Q0511: Whenever my system filter uses a \mail\ command to send a message, I get | |
3433 | the error \*User 0 set for address_reply transport is on the never_users | |
3434 | list*\. What does this mean? | |
3435 | ||
3436 | A0511: The system filter runs as \/root/\ in Exim 4, unless you set | |
3437 | \system_filter_user\ to specify otherwise. When you set up a delivery | |
3438 | direct from a system filter (an autoreply is a special kind of | |
3439 | ``delivery'') the transport runs as the same user, unless it has a | |
3440 | \user\ setting of its own. Normally, deliveries are not allowed to run | |
3441 | as \/root/\ as a security precaution; this is implemented by the | |
3442 | \never_users\ option. | |
3443 | ||
3444 | The easiest solution is to add this to your configuration: | |
3445 | ||
3446 | ==> system_filter_user = exim | |
3447 | ||
3448 | The system filter then runs as \/exim/\ instead of \/root/\. | |
3449 | Alternatively, you can arrange for autoreplies from the system filter to | |
3450 | use a special transport of their own, and set the \user\ option on that | |
3451 | transport. | |
3452 | ||
3453 | ||
3454 | Q0512: I'm trying to reference the ::Envelope-To:: header in my filter, but | |
3455 | \$h_envelope-to:$\ is always empty. | |
3456 | ||
3457 | A0512: ::Envelope-To:: is added at delivery time, by the transport. Therefore, | |
3458 | the header doesn't exist at filter time. In a user filter, the values | |
3459 | you probably want are in \$original_local_part$\ and | |
3460 | \$original_domain$\. In a system filter, the complete list of all | |
3461 | envelope recipients is in \$recipients$\. | |
3462 | ||
3463 | ||
3464 | Q0513: I want my system filter to freeze all mails greater than 500K in size, | |
3465 | but to exclude those to a specific domain. However, I don't seem to be | |
3466 | able to use \$domain$\ in a system filter. | |
3467 | ||
3468 | A0513: You cannot do this in a system filter, because a single message may have | |
3469 | multiple recipients, some in the special domain, and some not. That is | |
3470 | also the reason why \$domain$\ is not set in a system filter. | |
3471 | ||
3472 | If you want to take actions on a per-recipient basis, you have to do it | |
3473 | in a router. However, freezing is not appropriate, because freezing | |
3474 | stops all deliveries. You could, however, delay delivery to all but the | |
3475 | special domains by using something like this: | |
3476 | ||
3477 | ==> delay_if_too_big: | |
3478 | driver = redirect | |
3479 | domains = !the.special.domain | |
3480 | condition = ${if >{$message_size}{500K}{yes}{no}} | |
3481 | allow_defer | |
3482 | data = :defer: message too big. | |
3483 | ||
3484 | However, there isn't an easy way of ``releasing'' such messages at | |
3485 | present. | |
3486 | ||
3487 | ||
3488 | Q0514: When I try to send to two addresses I get an error in the filter | |
3489 | file \*malformed address: , e@fgh.com may not follow a@bcd.com*\. What | |
3490 | is going on? | |
3491 | ||
3492 | A0514: Have you got | |
3493 | ||
3494 | ==> deliver "a@bcd.com, e@fgh.com" | |
3495 | ||
3496 | in your filter? If so, that is your problem. You should have | |
3497 | ||
3498 | ==> deliver a@bcd.com | |
3499 | deliver e@fgh.com | |
3500 | ||
3501 | Each \deliver\ command expects just one address. | |
3502 | ||
3503 | ||
3504 | ||
3505 | 6. DELIVERY | |
3506 | ||
3507 | Q0601: What does the error \*Neither the xxx router nor the yyy transport set | |
3508 | a uid for local delivery of...*\ mean? | |
3509 | ||
3510 | A0601: Whenever Exim does a local delivery, it runs a process under a specific | |
3511 | user and group id (uid and gid). For deliveries into mailboxes, and to | |
3512 | pipes and files set up by forwarding, it normally picks up the uid/gid | |
3513 | of the receiving user. However, if an address is directed to a pipe or a | |
3514 | file by some other means, such an entry in the system alias file of the | |
3515 | form | |
3516 | ||
3517 | ==> majordomo: |/local/mail/majordomo ... | |
3518 | ||
3519 | then Exim has to be told what uid/gid to use for the delivery. This can | |
3520 | be done either on the routerr that handles the address, or on the | |
3521 | transport that actually does the delivery. If a pipe is going to run a | |
3522 | setuid program, then it doesn't matter what uid Exim starts it out with, | |
3523 | and so the most straightforward thing is to put | |
3524 | ||
3525 | ==> user = exim | |
3526 | ||
3527 | on either the router or the transport. A setting on the transport | |
3528 | overrides a setting on the router, so if the same transport is being | |
3529 | used with several routers, you should set the user on it only if you | |
3530 | want the same uid to be used in all cases. | |
3531 | ||
3532 | In the default configuration, the transports used for file and pipe | |
3533 | deliveries are the ones called \address_file\ and \address_pipe\. You | |
3534 | can specify different transports by setting, for example, | |
3535 | ||
3536 | ==> pipe_transport = special_pipe_transport | |
3537 | ||
3538 | on the \%system_aliases%\ router. Then you can set up \%special_pipe_transport%\ | |
3539 | ||
3540 | ==> special_pipe_transport: | |
3541 | driver = pipe | |
3542 | user = ???? | |
3543 | ||
3544 | which will be used only for pipe deliveries from that one router. | |
3545 | What you put for the ???? is up to you, and depends on the particular | |
3546 | circumstances. | |
3547 | ||
3548 | ||
3549 | Q0602: Exim keeps crashing with segmentation errors (signal 11 or 139) during | |
3550 | delivery. This seems to happen when it is about to contact a remote | |
3551 | host or when a delivery is deferred. | |
3552 | ||
3553 | A0602: This could be a problem with Exim's databases. Try running a delivery | |
3554 | with debugging turned on. If the last line of the debug output is | |
3555 | something like this: | |
3556 | ||
3557 | ==> locked /var/spool/exim/db/retry.lockfile | |
3558 | ||
3559 | the crash is happening inside the DBM library. Check that your DBM | |
3560 | library is correctly installed. In particular, if you have installed a | |
3561 | second DBM library onto a system that already had one, check that its | |
3562 | version of \(ndbm.h)\ is being seen first. For example, if the new | |
3563 | version is in \(/usr/local/include)\, check that there isn't another | |
3564 | version in \(/usr/include)\. If you are using Berkeley db, you can set | |
3565 | ||
3566 | ==> USE_DB=yes | |
3567 | ||
3568 | in your \(Local/Makefile)\ to avoid using \(ndbm.h)\ altogether. This is | |
3569 | particularly relevant for version 2 (or later) of Berkeley db, because | |
3570 | no \(ndbm.h)\ file is distributed with it. Another thing you can try is | |
3571 | to run | |
3572 | ||
3573 | ==> exim_dumpdb /var/spool/exim retry | |
3574 | ||
3575 | to see if it also crashes, or build the \^test_dbfn^\ tool and fiddle | |
3576 | around with it. If both fail, it is most almost certainly a problem with | |
3577 | your DBM library. You could try to update it, or force Exim to use | |
3578 | another library. See the file \(doc/dbm.discuss.txt)\ for hints about | |
3579 | this. | |
3580 | ||
3581 | ||
3582 | Q0603: How can mails that are being routed through routers that do not set | |
3583 | \check_local_user\ be delivered under the uid of the recipient? | |
3584 | ||
3585 | A0603: Q0601 contains background information on this. If you are using, say, an | |
3586 | alias file to direct messages to specific mailboxes, you can use | |
3587 | the \user\ option on either the router or the transport to set the uid. | |
3588 | What you put in the setting depends on how the required uid is to be | |
3589 | found. It could be looked up in a file or computed somehow from the | |
3590 | local part, for example. | |
3591 | ||
3592 | ||
3593 | Q0604: I want to use MMDF-style mailboxes. How can I get Exim to append the | |
3594 | ctrl-A characters that separate indvidual emails? | |
3595 | ||
3596 | A0604: Set the \message_suffix\ option in the \%appendfile%\ transport. In fact, | |
3597 | for MMDF mailboxes you need a prefix as well as a suffix to get it | |
3598 | working right, so your transport should contain these settings: | |
3599 | ||
3600 | ==> message_prefix = "\1\1\1\1\n" | |
3601 | message_suffix = "\1\1\1\1\n" | |
3602 | ||
3603 | Also, you need to change the \check_string\ and \escape_string\ settings so | |
3604 | that the escaping happens for lines in the message that happen to begin | |
3605 | with the MMDF prefix or suffix string, rather than ``From'' (the default): | |
3606 | ||
3607 | ==> check_string = "\1\1\1\1\n" | |
3608 | escape_string = "\1\1\1\1 \n" | |
3609 | ||
3610 | Adding a space to the line is sufficient to prevent it being taken as a | |
3611 | separator. | |
3612 | ||
3613 | ||
3614 | Q0605: If a user's mailbox is over quota, is there a way for me to set it up so | |
3615 | that the mail bounces to the sender and is not stored in the mail queue? | |
3616 | ||
3617 | A0605: In the retry section of the configuration, put | |
3618 | ||
3619 | ==> *@your.dom.ain quota | |
3620 | ||
3621 | That is, provide no retry timings for over quota errors. They will then | |
3622 | bounce immediately. Alternatively, you can set up retries for a short | |
3623 | time only, or use something like this: | |
3624 | ||
3625 | ==> *@your.dom.ain quota_7d | |
3626 | *@your.dom.ain quota F,2h,15m; F,3d,1h | |
3627 | ||
3628 | which bounces immediately if the user's mailbox hasn't been read for 7 | |
3629 | days, but otherwise tries for up to 3 days after the first quota | |
3630 | failure. | |
3631 | ||
3632 | ||
3633 | Q0606: I'm using tmail to do local deliveries, but when I turned on the | |
3634 | \use_crlf\ option on the \%pipe%\ transport (tmail prefers \"@\r@\n"\ | |
3635 | terminations) message bodies started to vanish. | |
3636 | ||
3637 | A0606: You need to unset the \mesage_prefix\ option, or change it so that its | |
3638 | default \"@\n"\ terminator becomes \"@\r@\n"\. For example, the | |
3639 | transport could be: | |
3640 | ||
3641 | ==> local_delivery_mbx: | |
3642 | driver = pipe | |
3643 | command = /usr/local/bin/tmail $local_part | |
3644 | user = exim | |
3645 | current_directory = / | |
3646 | use_crlf | |
3647 | message_prefix = | |
3648 | ||
3649 | The reason for this is as follows: tmail uses the line terminator on | |
3650 | the first line it sees to determine whether lines are terminated by | |
3651 | \"@\r@\n"\ or \"@\n"\. If the latter, it moans to stderr and changes subsequent | |
3652 | \"@\n"\ terminators to \"@\r@\n"\. The default setting of the \message_prefix\ | |
3653 | option is \"From ...@\n"\, and this is unaffected by the \use_crlf\ option. | |
3654 | If you don't change this, tmail sees the first line terminated by | |
3655 | \"@\n"\ and prepends \"@\r"\ to the \"@\n"\ terminator on all subsequent | |
3656 | lines. However, if \use_crlf\ is set, Exim makes all other lines | |
3657 | \"@\r@\n"\ terminated, leading to doubled \"@\r@\r@\n"\ lines and | |
3658 | corrupt mbx mailboxes. | |
3659 | ||
3660 | ||
3661 | Q0607: When I activate ``return receipt'' for example in Netscape Mailbox | |
3662 | sending options, then I get an error message from Exim... something | |
3663 | like \*not supported*\. Can I activate delivery confirmations? | |
3664 | ||
3665 | A0607: Exim does not support any kind of delivery notification. | |
3666 | ||
3667 | (1) You can configure it to recognize headers such as | |
3668 | \Return-receipt-to:\ if you wish. | |
3669 | ||
3670 | (2) Some people want MSN (message status notification). Such services | |
3671 | are implemented in MUAs, and don't impact on the MTA at all. | |
3672 | ||
3673 | (3) I investigated the RFCs which describe the DSN (delivery status | |
3674 | notification) system. However, I was unable to specify any sensible way | |
3675 | of actually doing anything with the data. There were comments on the | |
3676 | mailing list at the time; many people, including me, conclude that DSN | |
3677 | is in practice unworkable. The killer problem is with forwarding and | |
3678 | aliasing. Do you propagate the DSN data with the generated addresses? | |
3679 | Do you send back a ``reached end of the DSN world'' or ``expanded'' message? | |
3680 | Do you do this differently for different kinds of aliasing/forwarding? | |
3681 | For a user who has a \(.forward)\ file with a single address in, this | |
3682 | might seem easy - just propagate the data. But what if there are several | |
3683 | forwardings? If you propagate the DSN data, the sender may get back | |
3684 | several DSN messages - and should the sender really know about the | |
3685 | detail of the receiver's forwarding arrangements? There isn't really | |
3686 | any way to distinguish between a \(.forward)\ file that is forwarding | |
3687 | and one that is a mini mailing list. And so on, and so on. There are so | |
3688 | many questions that don't have obvious answers. | |
3689 | ||
3690 | ||
3691 | Q0608: What does the message \*retry time not reached [for any host]*\ on the log | |
3692 | mean? Why won't Exim try to deliver the message? | |
3693 | ||
3694 | A0608: That is not an error. It means exactly what it says. A previous attempt | |
3695 | to deliver to that address failed with a temporary error, and Exim | |
3696 | computed the earliest time at which to try again. This can apply to | |
3697 | local as well as to remote deliveries. For remote deliveries, each host | |
3698 | (if there are several) has its own retry time. | |
3699 | ||
3700 | If you are running on a dial-up host, the rest of this answer probably | |
3701 | does not apply to you. Go and read Q1404 instead. If your host is | |
3702 | permanently online, read on... | |
3703 | ||
3704 | Some MTAs have a retrying schedule for each message. Exim does not work | |
3705 | like this. Retry timing is normally host-based for remote deliveries and | |
3706 | address-based for local deliveries. (There are some exceptions for certain | |
3707 | kinds of remote failure - see \*Errors in outgoing SMTP*\ in the manual.) | |
3708 | ||
3709 | If a new message arrives for a failing address and the retry time has | |
3710 | not yet arrived, Exim will log \*retry time not reached*\ and leave the | |
3711 | message on the queue, without attempting delivery. Similarly, if a queue | |
3712 | runner notices the message before the time to retry has arrived, it | |
3713 | writes the same log entry. When the retry time has past, Exim attempts | |
3714 | delivery at the next queue run. If you want to know when that will be, | |
3715 | run the exinext utility on the address, for example: | |
3716 | ||
3717 | ==> exinext user@some.domain | |
3718 | ||
3719 | You can suppress these messages on the log by including \"-retry_defer"\ | |
3720 | in the setting of \log_selector\. You can force a delivery attempt on a | |
3721 | specific message (overriding the retry time) by means of the -M option: | |
3722 | ||
3723 | ==> exim -M 10hCET-0000Bf-00 | |
3724 | ||
3725 | If you want to do this for the entire queue, use the \-qf-\ option. | |
3726 | ||
3727 | ||
3728 | Q0609: Exim seems to be sending the same message twice, according to the log, | |
3729 | although there is a difference in capitalization of the local part of | |
3730 | the address. | |
3731 | ||
3732 | A0609: That is correct. The RFCs are explicit in stating that capitalization | |
3733 | matters for local parts. For remote domains, Exim is not entitled to | |
3734 | assume case independence of local parts. I know, it is utterly silly, | |
3735 | and it causes a lot of grief, but that's what the rules say. Here is a | |
3736 | quote from RFC 2821: | |
3737 | ||
3738 | ... a command verb, an argument value other than a mailbox local-part, | |
3739 | and free form text MAY be encoded in upper case, lower case, or any | |
3740 | mixture of upper and lower case with no impact on its meaning. This | |
3741 | is NOT true of a mailbox local-part. The local-part of a mailbox | |
3742 | MUST BE treated as case sensitive. Therefore, SMTP implementations | |
3743 | MUST take care to preserve the case of mailbox local-parts. Mailbox | |
3744 | domains are not case sensitive. In particular, for some hosts the | |
3745 | user "smith" is different from the user "Smith". However, exploiting | |
3746 | the case sensitivity of mailbox local-parts impedes interoperability | |
3747 | and is discouraged. | |
3748 | ||
3749 | ||
3750 | Q0610: How can I force the next retry time for a host to be now? | |
3751 | ||
3752 | A0610: You can change the retry time with the \^exim_fixdb^\ utility, but its | |
3753 | interface is very clumsy. If you have a message for the host on the | |
3754 | queue, the simplest thing to do is to force a delivery with the \-M-\ | |
3755 | command line option. If delivery succeeds, the retry data will get | |
3756 | cleared. If the host is past the cutoff time, so that messages are | |
3757 | bouncing immediately without trying a delivery, you can use \-odq-\ to | |
3758 | put a message on the queue without a delivery attempt, and then use | |
3759 | \-M-\ on it. | |
3760 | ||
3761 | ||
3762 | Q0611: I set up \"|/bin/grep Subject|/usr/bin/smbclient -M <netbiosname>"\ as an | |
3763 | alias but it doesn't work. | |
3764 | ||
3765 | A0611: That is a shell command line. Exim does not run pipe commands under a | |
3766 | shell by default (for added security - and it saves a process). You | |
3767 | need something like | |
3768 | ||
3769 | ==> "|/bin/sh -c '/bin/grep Subject|/usr/bin/smbclient -M <netbiosname>'" | |
3770 | ||
3771 | ||
3772 | Q0612: Why does the \%pipe%\ transport add a line starting with \">From"\ to | |
3773 | messages? | |
3774 | ||
3775 | A0612: Actually, it adds a line starting with \"From"\ followed by a space. | |
3776 | This is commonly referred to as the \"From_"\ line, to emphasize the | |
3777 | fact that \"From"\ is followed by a space and not a colon. This is a | |
3778 | pseudo-header line that contains the envelope sender address and the | |
3779 | time of delivery. It originated as a separator line in Berkeley format | |
3780 | mailboxes, but is also used in other contexts. (And yes, it is often | |
3781 | confused with the ::From:: header line, and this causes a lot of grief. | |
3782 | The use of \"From_"\ was one of the really bad email design decisions.) | |
3783 | ||
3784 | Exim's \%pipe%\ transport adds this pseudo-header line by default | |
3785 | because \(/usr/ucb/vacation)\ needs it, and that is one of the the most | |
3786 | common uses of piping. The \^procmail^\ local delivery agent also makes | |
3787 | use of the \"From_"\ line. If you do not want it, change the setting of | |
3788 | \message_prefix\ on the \%pipe%\ transport. For example, to remove the | |
3789 | line altogether, use | |
3790 | ||
3791 | ==> message_prefix = | |
3792 | ||
3793 | If you are not piping to \(/usr/ucb/vacation)\ or \^procmail^\, it is | |
3794 | likely that you do not need a \"From_"\ line, and indeed it may cause | |
3795 | problems if it is present. | |
3796 | ||
3797 | One user reported that this line gave trouble when a pipe was used to | |
3798 | send messages to Courier's \^deliverquota^\ program. The line was | |
3799 | retained with the message, and caused problems for MS Exchange 2000 when | |
3800 | retrieving messages with its built-in POP collector. Specifically, it | |
3801 | caused Exchange to not be able to recognise message attachments. | |
3802 | ||
3803 | ||
3804 | Q0613: I have set \fallback_hosts\ on my \%smtp%\ transport, but after the error | |
3805 | \*sem@chat.ru cannot be resolved at this time*\ Exim isn't using them. | |
3806 | ||
3807 | A0613: \fallback_hosts\ works only if an attempt at delivery to the original | |
3808 | host(s) fails. In this case, Exim couldn't even resolve the domain | |
3809 | \(chat.ru)\ to discover what the original hosts were, so it never got as far | |
3810 | as the transport. However, see Q0315 for a possible solution. | |
3811 | ||
3812 | ||
3813 | Q0614: After the holidays my ISP has always hundreds of e-mails waiting for me. | |
3814 | These are forced down Exim's throat in one go. Exim spawns a lot of | |
3815 | kids, but is there some limit to the number of processes it creates? | |
3816 | ||
3817 | A0614: Unless you have changed \smtp_accept_queue_per_connection\ it should | |
3818 | spawn only that many processes per connection (default 10). Your ISP | |
3819 | may be making many connections, of course. That is limited by | |
3820 | \smtp_accept_max\. | |
3821 | ||
3822 | ||
3823 | Q0615: When a message in the queue got to 12h old, Exim wrote \*retry timeout | |
3824 | exceeded*\ and removed all messages in the queue to this host - even | |
3825 | recent messages. How I can avoid this behaviour? I only want to remove | |
3826 | messages that have exceeded the maximum retry time. | |
3827 | ||
3828 | A0615: Exim's retrying is host-based rather than message-based. The philosophy | |
3829 | is that if a host has been down for a very long time, there is no point | |
3830 | in keeping messages hanging around. However, you might like to check | |
3831 | out \delay_after_cutoff\ in the \%smtp%\ transport. It doesn't do what you | |
3832 | want, but it might help. | |
3833 | ||
3834 | ||
3835 | Q0616: Can Exim add a ::Content-Length:: header to messages it delivers? | |
3836 | ||
3837 | A0616: You could include something like | |
3838 | ||
3839 | ==> headers_remove = "content-length" | |
3840 | headers_add = "Content-Length: $message_body_size" | |
3841 | ||
3842 | to the \%appendfile%\ transport. However, the use of ::Content-Length:: can | |
3843 | cause several problems, and is not recommended unless you really know | |
3844 | what you are doing. There is a discussion of the problems in | |
3845 | \?http://home.netscape.com/eng/mozilla/2.0/relnotes/demo/content-length.html?\. | |
3846 | ||
3847 | ||
3848 | Q0617: Exim seems to be trying to deliver a message every 10 minutes, though | |
3849 | the retry rules specify longer times after a while, because it is | |
3850 | writing a log entry every time, like this: | |
3851 | ||
3852 | ==> 1999-08-26 14:51:19 11IVsE-000MuP-00 == example@example.com T=smtp defer | |
3853 | (-34): some host address lookups failed and retry time not reached for | |
3854 | other hosts or connection limit reached | |
3855 | ||
3856 | A0617: It is looking at the message every 10 minutes, but it isn't actually | |
3857 | trying to deliver. It's looking up \(example.com)\ in the DNS and finding | |
3858 | this information: | |
3859 | ||
3860 | ==> example.com. MX 10 example-com.isp.example.com. | |
3861 | example.com. MX 0 mail.example.com. | |
3862 | mail.example.com. A 202.77.183.45 | |
3863 | A lookup for example-com.isp.example.com. yielded NXDOMAIN | |
3864 | ||
3865 | The last line means that there is no address (A) record in the DNS for | |
3866 | \(example-com.isp.example.com)\. That accounts for \*some host address | |
3867 | lookups failed*\, but the retry time for \(mail.example.com)\ hasn't been | |
3868 | reached, which accounts for \*retry time not reached for other hosts*\. | |
3869 | ||
3870 | ||
3871 | Q0618: I am trying to set exim up to have a automatic failover if it sees that | |
3872 | the system that it is sending all mail to is down. | |
3873 | ||
3874 | A0618: Add to the \%remote_smtp%\ transport the following: | |
3875 | ||
3876 | ==> fallback_hosts = failover.server.name(s) | |
3877 | ||
3878 | If there are several names, they must be separated by colons. | |
3879 | ||
3880 | ||
3881 | Q0619: I can't get Exim to deliver over NFS. I get the error \*fcntl() failed: | |
3882 | No locks available*\, though the lock daemon is running on the NFS server | |
3883 | and other hosts are able to access it. | |
3884 | ||
3885 | A0619: Check that you have \(lockd)\ running on the NFS client. This is not | |
3886 | always running by default on some systems (Red Hat is believed to be one | |
3887 | such system). | |
3888 | ||
3889 | ||
3890 | Q0620: Why does Exim bounce messages without even attempting delivery, giving | |
3891 | the error \*retry time not reached for any host after a long failure | |
3892 | period*\? | |
3893 | ||
3894 | A0620: This message means that all hosts to which the message could be sent | |
3895 | have been failing for so long that the end of the retry period | |
3896 | (typically 4 or 5 days) has been reached. In this situation, Exim still | |
3897 | computes a next time to retry, but any messages that arrive in the | |
3898 | meantime are bounced straight away. You can alter this behaviour by | |
3899 | unsetting the \delay_after_cutoff\ option on the smtp transport. Then Exim | |
3900 | will try most messages for those hosts once before giving up. | |
3901 | ||
3902 | ||
3903 | Q0621: My \(.forward)\ file is \"|/usr/bin/procmail -f-"\ and mail gets delivered, | |
3904 | but there was a bounce to the sender, sending him the output of procmail. | |
3905 | How can I prevent this? | |
3906 | ||
3907 | A0621: Exim's default configuration is set up like this: | |
3908 | ||
3909 | ==> address_pipe: | |
3910 | driver = pipe | |
3911 | return_output | |
3912 | ||
3913 | The \return_output\ option requests that any output that the pipe | |
3914 | produces be returned to the sender. That is the safest default. If you | |
3915 | don't want this, you can either remove the option altogether, or change | |
3916 | it to \return_fail_output\, to return output only if the command fails. | |
3917 | Note that this will affect all pipes that users run, not just your | |
3918 | procmail one. It might be better to arrange for procmail not to produce | |
3919 | any output when it succeeds. | |
3920 | ||
3921 | ||
3922 | Q0622: Can I write an ordinary file when I run a perl script as a transport | |
3923 | filter for the \%remote_smtp%\ and \%address_pipe%\ transports? | |
3924 | ||
3925 | A0622: Yes, provided the file is writeable by the uid under which the transport | |
3926 | runs (the Exim user in the case of the remote transport). However, if two | |
3927 | messages are being delivered at once, their data will get mixed up in | |
3928 | the file unless you implement your own locking scheme. If all you want | |
3929 | to do is to take a copy of the message, another approach that avoids | |
3930 | the locking problem is to use a system filter to set up an ``unseen'' | |
3931 | delivery to a file. If you only want the message's headers, you can | |
3932 | set \message_filter_file_transport\ to point to a special \%appendfile%\ | |
3933 | transport that has \headers_only\ set. | |
3934 | ||
3935 | ||
3936 | Q0623: My \(/var/spool/mail)\ has grown drastically. Is there any possibility of | |
3937 | using two directories? | |
3938 | ||
3939 | A0623: You can use an expansion string to split mailboxes between two | |
3940 | directories. For example, | |
3941 | ||
3942 | ==> file = /var/spool/mail${nhash_2:$local_part}/$local_part | |
3943 | ||
3944 | which does a hash on the local part, producing either 0 or 1, thereby | |
3945 | using \(mail0) or \(mail1)\. But remember, the MUAs that read these mailboxes | |
3946 | also have to know where they are. | |
3947 | ||
3948 | ||
3949 | Q0624: Sendmail has a program called \^smrsh^\ that restricts what binaries | |
3950 | can be run from sendmail aliases. Is there something like this in Exim ? | |
3951 | ||
3952 | A0624: Check out the \allow_commands\ option in the \%pipe%\ transport. | |
3953 | ||
3954 | ||
3955 | Q0625: I wish to have large emails go out one at a time. | |
3956 | ||
3957 | A0625: One possibility is to set up a router that defers all large messages, | |
3958 | except in queue runs. Since queue runners deliver just one | |
3959 | message at a time, if you limited the number of simultaneous queue | |
3960 | runners to 1, you would get the effect you wanted. A suitable router | |
3961 | might be | |
3962 | ||
3963 | ==> defer_if_large_unless_queue_run: | |
3964 | driver = redirect | |
3965 | condition = ${if or{{queue_running}{<{$message_size}{200K}}}{no}{yes}} | |
3966 | allow_defer | |
3967 | data = :defer: too large for immediate delivery | |
3968 | no_verify | |
3969 | ||
3970 | Of course, this would always delay any large message until the next | |
3971 | queue runner, but if you run them fairly regularly, this shouldn't be a | |
3972 | huge problem, and may even be desirable. Note the use of \no_verify\ to | |
3973 | ensure that this router is not used when Exim is verifying addresses. | |
3974 | ||
3975 | ||
3976 | Q0626: Exim can route local parts independent of their case, but the Cyrus LMTP | |
3977 | daemon requires the correct case. How can I fix this? | |
3978 | ||
3979 | A0626: You need to rewrite the local part to the correct case before running | |
3980 | the router that routes to Cyrus. For example, if you require all lower | |
3981 | case, and your router is called \local_user\, put this router in front | |
3982 | of it: | |
3983 | ||
3984 | ==> lowercase_local: | |
3985 | driver = redirect | |
3986 | redirect_router = local_user | |
3987 | domains = +local_domains | |
3988 | data = ${lc:$local_part}@$domain | |
3989 | ||
3990 | The setting of \redirect_router\ causes processing of the rewritten | |
3991 | address to start at the next router, instead of the first router. See | |
3992 | also Q0630, and C045 for a more complete Cyrus configuration. | |
3993 | ||
3994 | ||
3995 | Q0627: Is there a command I can send to Exim to retry all queued messages | |
3996 | regardless of their retry schedule? | |
3997 | ||
3998 | A0627: The \-qff-\ option starts a queue runner that forces a delivery attempt | |
3999 | for all messages, including frozen ones. If you use \-qf-\, frozen | |
4000 | messages are skipped. | |
4001 | ||
4002 | ||
4003 | Q0628: I have the default retry rule, which I thought meant that Exim should | |
4004 | keep trying for four days, but it seems to be bouncing some messages | |
4005 | immediately. | |
4006 | ||
4007 | A0628: See Q0615 and Q0620. | |
4008 | ||
4009 | ||
4010 | Q0629: I'm having trouble with quotas and Courier, because Exim is not handling | |
4011 | maildirsize files. | |
4012 | ||
4013 | A0629: You will do better to move the quota handling to Courier. Use \^maildrop^\ | |
4014 | as your MDA rather than direct Exim delivery. This also has the | |
4015 | advantage that if you give web access to the mail spool (over \^sqwebmail^\) | |
4016 | you can then use the web front end to edit \^maildrop^\ filter files. | |
4017 | ||
4018 | ||
4019 | Q0630: How can I configure Exim to deliver to a Cyrus message store? | |
4020 | ||
4021 | A0630: (1) The reference manual contains an example that uses pipe delivery. | |
4022 | ||
4023 | (2) Here is a transport that uses LMTP delivery, assuming that | |
4024 | \$local_part$\ contains the username: | |
4025 | ||
4026 | ==> cyrus_inbox: | |
4027 | driver =lmtp | |
4028 | user = cyrus | |
4029 | socket = /var/cyrus/socket/lmtp | |
4030 | ||
4031 | (3) This is a transport that delivers direct to a non-inbox mailbox: | |
4032 | ||
4033 | ==> cyrus_mailbox: | |
4034 | driver = pipe | |
4035 | user = $local_part | |
4036 | message_prefix = | |
4037 | message_suffix = | |
4038 | log_fail_output | |
4039 | return_output | |
4040 | command = "/usr/cyrus/bin/deliver -a $local_part \ | |
4041 | -m <mailbox-name> $local_part" | |
4042 | ||
4043 | This delivers to the Cyrus mailbox \"user.$local_part.<mailbox-name>"\. | |
4044 | Using \"user = $local_part"\ and \"-a $local_part"\ makes it work | |
4045 | without needing an explicit `p' ACL set for `anyone' on the mailbox. | |
4046 | ||
4047 | ||
4048 | Q0631: I would like to choose a retry rule based on on the sender rather than | |
4049 | the recipient address. Is this possible? | |
4050 | ||
4051 | A0631: Yes. The address part of a retry rule is matched as a single-item | |
4052 | address list. Such lists are always expanded, so you can use something | |
4053 | like this: | |
4054 | ||
4055 | ==> "${if eq{$sender_address}{xxx}{*@*}{no@no}}" quota F,1h,10m; ... | |
4056 | ||
4057 | If the sender address is ``xxx'', the pattern expands to ``*@*'', which | |
4058 | matches all recipient addresses; if you want to, you can make this a | |
4059 | more restrictive pattern. If the sender address is not ``xxx'', the | |
4060 | pattern expands to ``no@no'', which is assumed to be a recipient address | |
4061 | that can never match, so the retry rule is skipped. | |
4062 | ||
4063 | ||
4064 | Q0632: What does the error \*User 1 set for local_mbx_delivery transport is on | |
4065 | the never_users list*\ mean? | |
4066 | ||
4067 | A0632: You have configured the \%local_mbx_delivery%\ to run as the user whose | |
4068 | id (uid) is 1. However, this user is on the list defined by the | |
4069 | \never_users\ runtime option, or the \\FIXED_NEVER_USERS\\ compile-time | |
4070 | option. These are ``safety catch'' lists; Exim refuses to deliver to any | |
4071 | user that is on them. The most common use of \never_users\ is to avoid | |
4072 | doing any deliveries as \/root/\, but it can contain other uids. | |
4073 | ||
4074 | ||
4075 | Q0633: Why is \$domain$\ not set in the \%smtp%\ transport? | |
4076 | ||
4077 | A0633: The \%smtp%\ transport can handle several recipient addresses at once. | |
4078 | This happens by default if the host lists for the addresses are | |
4079 | identical. A single copy of the message is sent, using multiple \\RCPT\\ | |
4080 | commands to transmit multiple envelope recipients. The \$domain$\ | |
4081 | variable is set in the \%smtp%\ transport only if all the recipient | |
4082 | addresses have the same domain. You must have a case where several | |
4083 | addresses with different domains resolve to the same set of hosts. | |
4084 | ||
4085 | If you want to restrict the transport so that it handles only a single | |
4086 | domain at once (but still possibly with more than one recipient), set | |
4087 | ||
4088 | ==> multi_domain = false | |
4089 | ||
4090 | If you want to restrict the transport so that it handles only a single | |
4091 | address at once, set | |
4092 | ||
4093 | ==> max_rcpt = 1 | |
4094 | ||
4095 | ||
4096 | Q0634: How can I stop a local transport from trying to access the user's home | |
4097 | directory, even when the delivery is to a file that is elsewhere? | |
4098 | ||
4099 | A0634: See answer (2) for Q0423. | |
4100 | ||
4101 | ||
4102 | Q0635: The log message \*error ignored*\ appears after some delivery failures. | |
4103 | What does it mean? | |
4104 | ||
4105 | A0635: This message is written when Exim fails to deliver a bounce message whose | |
4106 | age is greater than \ignore_bounce_errors_after\. It indicates that the | |
4107 | failing bounce message has been discarded. | |
4108 | ||
4109 | The same message is written after failed deliveries when a filter file | |
4110 | uses the \noerror\ feature when setting up a delivery, or if a router | |
4111 | has the setting | |
4112 | ||
4113 | ==> errors_to = <> | |
4114 | ||
4115 | Both of these specify that delivery failures are to be discarded. | |
4116 | ||
4117 | ||
4118 | ||
4119 | 7. POLICY CONTROLS | |
4120 | ||
4121 | Q0701: How do I block unwanted messages from outside my host? | |
4122 | ||
4123 | A0701: Exim uses Access Control Lists (ACLs) for controlling incoming mail from | |
4124 | other hosts. A whole chapter in the reference manual is devoted to | |
4125 | describing how they work. A wide variety of conditions can be imposed on | |
4126 | incoming messages. | |
4127 | ||
4128 | The default Exim run time configuration contains an example of an ACL | |
4129 | which blocks all relaying, and messages whose senders cannot be | |
4130 | verified. This example is heavily commented and worth studying. | |
4131 | ||
4132 | ||
4133 | Q0702: I don't want to block spam entirely; how can I inspect each message | |
4134 | before deciding whether or not to deliver it? | |
4135 | ||
4136 | A0702: Wherever possible, inspection and rejection is best done automatically | |
4137 | in an ACL, that is, before the message is accepted. If you want to | |
4138 | verify manually each message that is classified as spam by an automatic | |
4139 | check, you can arrange for a system filter to freeze such messages after | |
4140 | they have been accepted. | |
4141 | ||
4142 | If, after inspection, you decide not to deliver the message, it is | |
4143 | safest to discard it, using the \-Mrm-\ option. Use of the \-Mg-\ option | |
4144 | to force a bounce carries the risk of ``collateral spam'' if the sender | |
4145 | address is faked. | |
4146 | ||
4147 | ||
4148 | Q0703: How can I test that my spam blocks are working? | |
4149 | ||
4150 | A0703: The \-bh-\ option allows you to run a testing SMTP session as if from a | |
4151 | given IP address. For example, | |
4152 | ||
4153 | ==> exim -bh 192.168.178.39 | |
4154 | ||
4155 | In addition to the normal SMTP replies, it outputs commentary about | |
4156 | which tests have succeeded or failed. If you are not interested in the | |
4157 | details, but just want to know if a particular sender at a particular IP | |
4158 | address is able to mail to a particular recipient, you can use the | |
4159 | \exim_checkaccess\ utility, which provides a ``packaged'' version of | |
4160 | \-bh-\. You call it like this: | |
4161 | ||
4162 | ==> exim_checkaccess 192.168.53.23 recip@my.domain -f sender@some.domain | |
4163 | ||
4164 | If you don't give a sender, \"<>"\ is used (that it, it acts like a | |
4165 | bounce message). | |
4166 | ||
4167 | ||
4168 | Q0704: How can I test that Exim is correctly configured to use the Realtime | |
4169 | Blackhole List (RBL)? | |
4170 | ||
4171 | A0704: The \-bh-\ option allows you to run a testing SMTP session as if from a | |
4172 | given address. The \^exim_checkaccess^\ utility provides a more packaged | |
4173 | version of this facility. You need to know a blocked IP address with | |
4174 | which to test. Such a testing address is kindly provided by Russell | |
4175 | Nelson: | |
4176 | ||
4177 | ==> linux.crynwr.com [192.203.178.39] | |
4178 | ||
4179 | You can also send mail to \(nelson@linux.crynwr.com)\ from the server | |
4180 | whose RBL block you are testing. The robot that receives that email | |
4181 | will attempt to send a piece of test email in reply. If your RBL block | |
4182 | didn't work, you get a message to that effect. Regardless of whether the | |
4183 | RBL block succeeds or not, it emails you the results of the SMTP | |
4184 | conversation from a host that is not on the RBL, so you can see how your | |
4185 | server looks from the view of someone on the RBL. | |
4186 | ||
4187 | ||
4188 | Q0705: How can I use tcpwrappers in conjunction with Exim? | |
4189 | ||
4190 | A0705: Exim's own control facilities can do all that tcpwrappers can do. | |
4191 | However, if you are already using tcpwrappers for other things it might | |
4192 | be convenient to include Exim controls in the same place. | |
4193 | ||
4194 | First of all, ensure that Exim is built to call the tcpwrappers library, | |
4195 | by including \\USE_TCPWRAPPERS=yes\\ in \(Local/Makefile)\. You also need to | |
4196 | ensure that the header file \(tcpd.h)\ is available at compile time, and the | |
4197 | \(libwrap.a)\ library is available at link time, typically by including it in | |
4198 | \\EXTRALIBS\\. You may need to copy these two files from the tcpwrappers | |
4199 | build directory to, for example, \(/usr/local/include)\ and \(/usr/local/lib)\, | |
4200 | respectively. Then you could reference them by | |
4201 | ||
4202 | ==> CFLAGS=-I/usr/local/include | |
4203 | EXTRALIBS=-L/usr/local/lib -lwrap | |
4204 | ||
4205 | in \(Local/Makefile)\. There are two ways to make use of the functionality, | |
4206 | depending on how you have tcpwrappers set up. If you have it set up to | |
4207 | use only one file, you ought to have something like: | |
4208 | ||
4209 | ==> /etc/hosts.allow: | |
4210 | ||
4211 | ==> exim : <client_list> : <allow_or_deny> | |
4212 | ||
4213 | For example: | |
4214 | ||
4215 | ==> exim : LOCAL 192.168.0. .friendly.domain special.host : ALLOW | |
4216 | exim : ALL : DENY | |
4217 | ||
4218 | This allows connections from local hosts (chiefly //localhost//), from | |
4219 | the subnet 192.168.0.0/24, from all hosts in \(*.friendly.domain)\, and | |
4220 | from a specific host called \(special.host)\. All other connections are | |
4221 | denied. If you have tcpwrappers set up to use two files, use the | |
4222 | following: | |
4223 | ||
4224 | ==> /etc/hosts.allow: | |
4225 | ||
4226 | ==> exim : <client_list> | |
4227 | ||
4228 | ==> /etc/hosts.deny: | |
4229 | ||
4230 | ==> exim : <client_list> | |
4231 | ||
4232 | Read the \^hosts_access^\ man page for more ways of specifying clients, | |
4233 | including ports, etc., and on logging connections. | |
4234 | ||
4235 | ||
4236 | Q0706: How can I get POP-auth-before-relay (aka POP-before-SMTP) support in | |
4237 | Exim? | |
4238 | ||
4239 | A0706: Exim 4 supports the ``whoson'' (\?http://whoson.sourceforge.net?\) | |
4240 | facility for doing this. If you set this up, you can do the check in an | |
4241 | Exim ACL by a statement like this: | |
4242 | ||
4243 | ==> require condition = \ | |
4244 | ${lookup whoson {$sender_host_address}{yes}{no}} | |
4245 | ||
4246 | Otherwise you need to arrange for a list of permitted IP addresses to be | |
4247 | maintained in a file or database, and use this in a \hosts\ condition in | |
4248 | an ACL statement. An Exim user has published this recipe: | |
4249 | ||
4250 | \#\#\#\#\?http://www.zeiss.cx/memo/computer/linux/email/exim-s-a-p.html?\ | |
4251 | ||
4252 | Another Exim user submitted the following idea: | |
4253 | ||
4254 | Use a script to grab authenticated IP addresses from the log files of | |
4255 | the POP3 and IMAP4 daemons. These are used to create files in the | |
4256 | directory tree \(/var/db/popb4smtp)\. The existence of a file represents a | |
4257 | valid ``popped recently token'' for the IP address used as the filename. | |
4258 | ||
4259 | Another script periodically removes stale files from the tree (after two | |
4260 | hours). There's a small race condition here; it's possible for a file | |
4261 | to be deleted just after it has been updated by the script that watches | |
4262 | the logs. For low-volume servers, the odds of hitting this window are | |
4263 | low. | |
4264 | ||
4265 | A POPB4SMTP_CLIENT macro in the Exim configure file provides a reusable | |
4266 | ``has this sender popped recently?'' query: | |
4267 | ||
4268 | ==> POPB4SMTP_SUBDIR = /var/db/popb4smtp/${substr_-1_1:$sender_host_address} | |
4269 | POPB4SMTP_CLIENT = ${if exists {POPB4SMTP_SUBDIR/$sender_host_address} \ | |
4270 | {$sender_host_address} {0} } | |
4271 | ||
4272 | Now you can use it just about anywhere, including in your ACLs. Simple | |
4273 | examples include: | |
4274 | ||
4275 | ==> hostlist relay_hosts = 127.0.0.1/32 : ... : POPB4SMTP_CLIENT | |
4276 | host_lookup = !127.0.0.1/32 : ... : !POPB4SMTP_CLIENT | |
4277 | rfc1413_hosts = !127.0.0.1/32 : ... : !POPB4SMTP_CLIENT | |
4278 | ||
4279 | The two scripts (and a FreeBSD startup script for them) are available | |
4280 | for download at: | |
4281 | ||
4282 | \#\#\#\#\?http://people.FreeBSD.org/~sheldonh/popb4smtp-nodb.tar.gz?\ | |
4283 | ||
4284 | ||
4285 | Q0707: I have one or two cases where my host correctly rejects messages, but | |
4286 | the remote host is quite persistent, and keeps trying over and over. | |
4287 | ||
4288 | A0707: It is an unfortunate fact that a number of SMTP clients, in violation of | |
4289 | the SMTP RFC, do not treat a permanent error code that is given after | |
4290 | the DATA portion of the transaction as a permanent error. Consequently | |
4291 | they keep resending the message, and the worst offenders do so at very | |
4292 | short intervals. | |
4293 | ||
4294 | The only way to stop such behaviour is to blacklist the IP address, or | |
4295 | the envelope sender, or both, in such a way that future messages get | |
4296 | rejected at RCPT time instead of at DATA time. You could also complain | |
4297 | to the remote host's administrators. | |
4298 | ||
4299 | ||
4300 | Q0708: How can I run customized verification checks on incoming addresses? | |
4301 | ||
4302 | A0708: There are a number of possibilities: | |
4303 | ||
4304 | (1) If you can implement your checks in Perl, you can use Exim's | |
4305 | facility for running an embedded Perl interpreter. For example, if you | |
4306 | want to run special checks on local addresses, you could use ACL | |
4307 | an statement like this: | |
4308 | ||
4309 | ==> require domains = my.local.domain | |
4310 | condition = ${perl{verify}{$local_part}} | |
4311 | ||
4312 | The result of the Perl function should be ``yes'' or ``no''. | |
4313 | ||
4314 | (2) You could also run an external program in a similar way, by a | |
4315 | statement such as: | |
4316 | ||
4317 | ==> require domains = my.local.domain | |
4318 | condition = ${run{/my/verifier $local_part}} | |
4319 | ||
4320 | This requires the use of another process, so could prove more expensive | |
4321 | than Perl. | |
4322 | ||
4323 | (3) If you are prepared to write C code, read the chapter in the manual | |
4324 | entitled \*Adding a local scan function to Exim*\. | |
4325 | ||
4326 | ||
4327 | Q0709: Does Exim apply RBL checks to error messages, those with an envelope | |
4328 | sender of \"<>"\ ? | |
4329 | ||
4330 | A0709: This depends on the ACL configuration. You can test for bounce messages | |
4331 | (by looking for an empty sender address) and thereby exclude them from | |
4332 | RBL checking if you want. This ACL statement does that: | |
4333 | ||
4334 | ==> deny senders = ! : | |
4335 | dnslist = blackholes.mail-abuse.org | |
4336 | ||
4337 | However, some spam does come with an empty sender address, so this may | |
4338 | not be a good idea. | |
4339 | ||
4340 | ||
4341 | Q0710: I want to reject certain sender-recipient combinations, with a specific | |
4342 | message for each such combination. | |
4343 | ||
4344 | A0710: Set up a file (or database) containing the messages, keyed by the | |
4345 | combination, for example: | |
4346 | ||
4347 | ==> sender1@sdomain1=>recipient1@rdomain1: blocked because... | |
4348 | sender2@sdomain2=>recipient2@rdomain2: blocked because... | |
4349 | ||
4350 | If you have lots of recipients for the same sender, it might be easier | |
4351 | to generate this file from more convenient data. In your ACL that is run | |
4352 | for each RCPT command, you can then put: | |
4353 | ||
4354 | ==> deny message = ${lookup{$sender_address=>$local_part@$domain}\ | |
4355 | lsearch{/that/file}} | |
4356 | condition = ${lookup{$sender_address=>$local_part@$domain}\ | |
4357 | lsearch{/that/file}}{yes}{no}} | |
4358 | ||
4359 | The condition is tested first. If the lookup succeeds, the condition | |
4360 | succeeds so access is denied. The message is then expanded, but the | |
4361 | lookup won't be repeated, because Exim will have cached the previous | |
4362 | result. | |
4363 | ||
4364 | This approach blocks only incoming SMTP messages. If you need to do | |
4365 | similar blocks for messages that do not arrive over SMTP, you have to | |
4366 | set up a suitable \%redirect%\ router with a \:fail:\ setting. | |
4367 | ||
4368 | ||
4369 | Q0711: Will Exim allow me to create a file of regexs and match incoming | |
4370 | external email to the list - and if a match is found file the offending | |
4371 | message into a special location? Also is it possible to make Exim only | |
4372 | filter parts of an incoming email - e.g. ignore large MIME attachments | |
4373 | for example and only process text/plain? | |
4374 | ||
4375 | A0711: You can do some of this in a system filter. For example: | |
4376 | ||
4377 | ==> if $message_body matches <...some complicated regex...> or | |
4378 | $message_body matches <...some other regex...> or | |
4379 | $header_from: matches <...regex...> or | |
4380 | etc. | |
4381 | then | |
4382 | save /some/special/file | |
4383 | endif | |
4384 | ||
4385 | or instead of \"save"\ you could have \"deliver"\ (to some address) or | |
4386 | \"pipe"\ (to some script). | |
4387 | ||
4388 | There isn't any mechanism for ignoring attachments, but \$message_body$\ | |
4389 | only looks at the first n bytes of the body, where n defaults to 500 but | |
4390 | can be changed. | |
4391 | ||
4392 | A more expensive alternative would be to run a Perl subroutine using the | |
4393 | embedded Perl mechanism. If you passed over the message id, the Perl | |
4394 | code could read the message files on the spool and implement any | |
4395 | algorithm it liked for deciding what should be done. | |
4396 | ||
4397 | ||
4398 | Q0712: I've hacked sendmail to make an ioctl call at the time of the SMTP RCPT | |
4399 | command, to check if a user has exceeded their email quota. If they have | |
4400 | I issue a temporary failure and a message - can I do this with Exim? | |
4401 | ||
4402 | A0712: If you can make this happen in Perl you can use the embedded Perl | |
4403 | facility, and use it from a \condition\ condition in an ACL statement. | |
4404 | You can also use the expansion facility to run an external program, but | |
4405 | this uses more resources because it uses another process. | |
4406 | ||
4407 | ||
4408 | Q0713: I'd like to pass all messages through a virus-scanning system before | |
4409 | delivery. Can Exim do this? | |
4410 | ||
4411 | A0713: One way of achieving this is to deliver all messages via a pipe to a | |
4412 | checking program that resubmits them for delivery in some private way | |
4413 | that can be checked (e.g. on a specific SMTP port, or IP address). One | |
4414 | possibility is to use the `received protocol` field that can be set | |
4415 | for locally submitted mail via the \-oMr-\ command line option. This | |
4416 | router sends all messages that are not from the local host and whose | |
4417 | received protocol is not \"scanned-ok"\ to the \%virus_scan%\ transport: | |
4418 | ||
4419 | ==> vircheck: | |
4420 | driver = accept | |
4421 | transport = virus_scan | |
4422 | condition = ${if or {{eq {$received_protocol}{scanned-ok}} \ | |
4423 | {eq {$sender_host_address}{127.0.0.1}}}\ | |
4424 | {0}{1}} | |
4425 | ||
4426 | One problem is that this approach scans the message for each recipient, | |
4427 | not just once per message. | |
4428 | ||
4429 | The virus_scan transport should be set up to pipe the message to a | |
4430 | suitable checking program or script which runs as a trusted user. This | |
4431 | can then re-submit the message to Exim, using \-oMr-\ to set the received | |
4432 | protocol to \"scanned-ok"\, and the \-f-\ option to set the correct envelope | |
4433 | sender address. \**Warning:**\ If you forget to make the resubmitting process | |
4434 | run as a trusted user, the received protocol does not get set, and you | |
4435 | are likely to generate a loop. | |
4436 | ||
4437 | ||
4438 | Q0714: Is there a way to configure Exim to reject mail to a certain local host? | |
4439 | ||
4440 | A0714: No, only to certain domains. To reject at SMTP time, you can put a line | |
4441 | like this in your ACL: | |
4442 | ||
4443 | ==> deny message = this domain is deliberately rejected | |
4444 | domains = a.certain.domain | |
4445 | ||
4446 | To fail addresses in messages that do not arrive over SMTP, you can set | |
4447 | up a router like this: | |
4448 | ||
4449 | ==> reject_a_certain_domain: | |
4450 | driver = redirect | |
4451 | domains = a.certain.domain | |
4452 | allow_fail | |
4453 | data = :fail: this domain is deliberately rejected | |
4454 | ||
4455 | ||
4456 | Q0715: How can I get Exim to remove attachments from messages? | |
4457 | ||
4458 | A0715: Exim does not contain facilities for modifying messages. You must use | |
4459 | an external program if you want to do this. You can route messages that | |
4460 | have a ::Content-type:: header line via a pipe to a command that does | |
4461 | the job and then re-submits the message to Exim. Alternatively, you | |
4462 | could use a transport filter to do this job. | |
4463 | ||
4464 | ||
4465 | Q0716: How can I arrange for each user to have a file listing the only sender | |
4466 | addresses from which she will accept mail? I want to do this so my | |
4467 | family members don't get any spam (or other inappropriate mail). | |
4468 | ||
4469 | A0716: Let's assume each user has a file called \(.acceptlist)\ in the home | |
4470 | directory. You can put in your ACL a line like this: | |
4471 | ||
4472 | ==> require senders = /home/$local_part/.acceptlist | |
4473 | ||
4474 | This will reject RCPT commands when the sender is not in the accept | |
4475 | list for the recipient. (Replace \(/home/$local_part)\ with whatever | |
4476 | the correct path to your user's home directories is.) | |
4477 | ||
4478 | One problem with this is that it will block bounce messages, which have | |
4479 | empty senders. You can get round this, by changing the line to this: | |
4480 | ||
4481 | ==> require senders = : /home/$local_part/.acceptlist | |
4482 | ||
4483 | However, this will, of course, let in spam that has a null sender. | |
4484 | ||
4485 | ||
4486 | Q0717: When using Nessus on a system that runs Exim, a number of security | |
4487 | issues are raised. Nessus complains that Exim answers to EXPN and/or | |
4488 | VRFY; sometimes it even complains that Exim allows relaying. | |
4489 | ||
4490 | A0717: Exim supports EXPN and VRFY only if you permit it to do so in the ACLs | |
4491 | defined by \acl_smtp_expn\ and \acl_smtp_vrfy\, respectively. Otherwise, | |
4492 | its responses are | |
4493 | ||
4494 | ==> 550 Administrative prohibition | |
4495 | 252 Administrative prohibition | |
4496 | ||
4497 | Maybe the use of 252 is the ``problem''. It is recommended that this be | |
4498 | done (by those that discuss these things) because there are stupid | |
4499 | clients that attempt VRFY before sending a message. | |
4500 | ||
4501 | ||
4502 | Q0718: Could anyone points me to right rules to prevent sending/receiving | |
4503 | messages to/for domains which have one MX to localhost or only have | |
4504 | address 127.0.0.1 ? | |
4505 | ||
4506 | A0718: See Q0319. | |
4507 | ||
4508 | ||
4509 | Q0719: I would like to have a per-user limit for the maximum size of messages | |
4510 | that can be sent. | |
4511 | ||
4512 | A0719: The simplest way to do this is to put something in a system filter along | |
4513 | these lines: | |
4514 | ||
4515 | ==> if $message_size is above | |
4516 | "${lookup{$sender_address}lsearch{/some/file}{$value}{10M}}" | |
4517 | then | |
4518 | fail "Message is larger than $sender_address is allowed to send" | |
4519 | endif | |
4520 | ||
4521 | In practice, an additional check that the message has arrived from your | |
4522 | local host or local network is probably wise because sender addresses | |
4523 | are easily forged. | |
4524 | ||
4525 | ||
4526 | Q0720: I set \"accept hosts=192.168.122.96/32"\ in order to accept mail for | |
4527 | relaying from my local LAN, but it doesn't work. What's wrong? | |
4528 | ||
4529 | A0720: 192.168.122.96/32 is not a network, it is a single host. Exim uses CIDR | |
4530 | notation for specifying networks, where the number after the slash is | |
4531 | the number of bits in the IP address that must match. Your setting says | |
4532 | ``32 bits must match''. If you really mean to specify ``the next 32 | |
4533 | IP addresses'', you need 192.168.122.96/27. | |
4534 | ||
4535 | ||
4536 | Q0721: I have POP-before-SMTP set up on my Exim server, but some clients use | |
4537 | Outlook Express, which sends queued messages before checking the | |
4538 | mailbox, so it doesn't work. | |
4539 | ||
4540 | A0721: Implement SMTP authentication. | |
4541 | ||
4542 | ||
4543 | Q0722: I installed Amavis and it is working, but bounces are simply vanishing. | |
4544 | ||
4545 | A0722: Check that you haven't inadvertently set up the transport like this: | |
4546 | ||
4547 | ==> amavis: | |
4548 | driver = pipe | |
4549 | command = "/usr/sbin/amavis -f ${sender_address} -d ${pipe_addresses}" | |
4550 | ||
4551 | The last line should be: | |
4552 | ||
4553 | ==> command = /usr/sbin/amavis -f <$sender_address> -d $pipe_addresses | |
4554 | ||
4555 | The important thing is the <> around the sender address; removal of | |
4556 | the unnecessary "" and {} is just tidying. See the amavis FAQ at | |
4557 | \?http://www.amavis.org/amavis-faq.php3?\. | |
4558 | ||
4559 | ||
4560 | Q0723: I can't get Pine to work with PLAIN authentication; Exim keeps | |
4561 | responding "535 Incorrect authentication data". | |
4562 | ||
4563 | A0723: You need to have this setting in your PLAIN authenticator: | |
4564 | ||
4565 | ==> server_prompts = : | |
4566 | ||
4567 | This is missing in the examples in all but the most recent Exim | |
4568 | documentation, because it was not realized that PLAIN authentication | |
4569 | could be requested by a client without sending the data with the | |
4570 | request. If the data is not sent, an empty prompt is expected. | |
4571 | ||
4572 | ||
4573 | Q0724: I have used \":fail:"\ in some aliases; when one of these addresses is | |
4574 | refused, I see the message on the log, but the response to the remote | |
4575 | user is ``unknown user'' instead of the message from the alias file. | |
4576 | How can I change this? | |
4577 | ||
4578 | A0724: Have you got a \message\ qualifier in the relevant ACL? Exim uses the | |
4579 | message line in the ACL in preference to the message returned by the | |
4580 | router. This is so you can restrict the amount of information that | |
4581 | ``escapes'' from your site via SMTP if you want to. Remove the \message\ | |
4582 | line in the ACL entry that has \"verify = recipient"\ and your message | |
4583 | will get through. | |
4584 | ||
4585 | Alternatively, if you are running Exim 4.10 or later, you can use the | |
4586 | \$acl_verify_message$\ variable in your message to include the message | |
4587 | from the router. See also Q0725. | |
4588 | ||
4589 | ||
4590 | Q0725: I've set up some specific rejection messages for certain recipients, but | |
4591 | when I test them, the SMTP message is always \*550 5.1.1 | |
4592 | <user@mydomain.com>... User unknown*\. | |
4593 | ||
4594 | A0725: That is not an Exim message (the ``5.1.1'' is a clue; Exim doesn't use | |
4595 | those extended codes). You are probably being defeated by software that | |
4596 | sees the 550 error code, and insists on putting in its own text. There | |
4597 | is stupid software that does this. You can test Exim by using \-bh-\ or | |
4598 | making a telnet call to the SMTP port. That way, there's no other | |
4599 | software intervening. | |
4600 | ||
4601 | ||
4602 | Q0726: My SMTP authentication can be bypassed by sending an unknown user name | |
4603 | and an empty password. What is wrong with this condition in a PLAIN | |
4604 | authenticator? | |
4605 | ||
4606 | ==> server_condition = ${if eq{$2} {${lookup mysql{SELECT password FROM \ | |
4607 | accounts WHERE username='${local_part:$1}'}}}{1}{0}} | |
4608 | ||
4609 | A0726: Your lookup item returns an empty string when the user does not exist. | |
4610 | You should instead arrange for the lookup to fail: | |
4611 | ||
4612 | ==> server_condition = ${if eq{$2} {${lookup mysql{SELECT password FROM \ | |
4613 | accounts WHERE username='${local_part:$1}'}{$value}fail}}{1}{0}} | |
4614 | ||
4615 | ||
4616 | Q0727: When a message has many recipients, how can I stop SpamAssassin from | |
4617 | being called for each of them? I'm running it from a pipe transport. | |
4618 | ||
4619 | A0727: In the transport configuration, set \batch_max\ to a value greater than | |
4620 | one. | |
4621 | ||
4622 | ||
4623 | Q0728: How do I use Exiscan, SA-Exim, SpamAssassin, Clam Antivirus, Sophos | |
4624 | SAVI, or sophie with Exim? | |
4625 | ||
4626 | A0728: There's a mini-HOWTO about these available via | |
4627 | \?http://www.timj.co.uk/linux/exim.php?\. | |
4628 | See also sample configuration C047. | |
4629 | ||
4630 | ||
4631 | Q0729: How can I screen out addresses that are neither valid usernames or | |
4632 | distribution lists on mail being forwarded to an internal Win2K server? | |
4633 | ||
4634 | A0729: A user suggested using a router like this to do the recipient | |
4635 | verification: | |
4636 | ||
4637 | ==> verify_user_router: | |
4638 | driver = accept | |
4639 | domains = win2kdomain.com | |
4640 | local_parts=\ | |
4641 | ldap;user="cn=ldap-guest,cn=Users,dc=win2kdomain,dc=com"\ | |
4642 | pass=guest \ | |
4643 | ldap:://win2kpdc/dc=win2kdomain,dc=com?mailNickname?\ | |
4644 | sub?(&(mailNickname=$local_part)\ | |
4645 | (showInAddressBook=*)(sAMAccountName=*)) | |
4646 | verify_only | |
4647 | ||
4648 | Set up ldap-guest as a normal domain user on the Win2K PDC. | |
4649 | ||
4650 | Also, you need to set \no_verify\ on all the other routers that handle | |
4651 | that domain. | |
4652 | ||
4653 | ||
4654 | Q0730: How can I use the same passwords for SMTP authentication as I use for | |
4655 | Courier IMAP access to my server? | |
4656 | ||
4657 | A0730: You can access the Courier authdaemon from an Exim authenticator. You | |
4658 | must arrange for the Exim user (often \/exim/\ but sometimes \/mail/\) | |
4659 | to be able to access \(/var/run/courier/authdaemon/socket)\. The | |
4660 | configuration is something of a hack, but it is reported to work. Here | |
4661 | is a LOGIN authenticator: | |
4662 | ||
4663 | ==> login: | |
4664 | driver = plaintext | |
4665 | public_name = LOGIN | |
4666 | server_prompts = Username:: : Password:: | |
4667 | server_condition = \ | |
4668 | ${if eq {${readsocket{/var/run/courier/authdaemon/socket}\ | |
4669 | {AUTH 76\n${length_76:exim\nlogin\n$1\n$2\ | |
4670 | \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\ | |
4671 | \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\ | |
4672 | \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n}}}}{FAIL\n} {no}{yes}} | |
4673 | server_set_id = $1 | |
4674 | ||
4675 | Here is a PLAIN authenticator: | |
4676 | ||
4677 | ==> plain: | |
4678 | driver = plaintext | |
4679 | public_name = PLAIN | |
4680 | server_prompts = : | |
4681 | server_condition = \ | |
4682 | ${if eq {${readsocket{/var/run/courier/authdaemon/socket}\ | |
4683 | {AUTH 76\n${length_76:exim\nlogin\n$2\n$3\ | |
4684 | \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\ | |
4685 | \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\ | |
4686 | \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n}}}}{FAIL\n} {no}{yes}} | |
4687 | server_set_id = $2 | |
4688 | ||
4689 | ||
4690 | Q0731: Is there any defence I can use against spam sent through an open proxy? | |
4691 | ||
4692 | A0731: The \*ident*\ feature can be used in some cases. See the discussion in | |
4693 | Q5023. | |
4694 | ||
4695 | ||
4696 | Q0732: I would like to either warn or deny when a host uses an underscore in | |
4697 | the EHLO command. | |
4698 | ||
4699 | A0732: First, set | |
4700 | ||
4701 | ==> helo_allow_chars = _ | |
4702 | ||
4703 | This tells Exim not to reject the EHLO or HELO command immediately. Once | |
4704 | you have done that, you can test for the underscore in an ACL. For | |
4705 | example, to log a warning for hosts in your LAN, and reject for other | |
4706 | hosts, you could do something like this: | |
4707 | ||
4708 | ==> deny message = Underscores are not valid in host names | |
4709 | hosts = ! +lan_hosts | |
4710 | condition = ${if match{$sender_helo_name}{_}{yes}{no}} | |
4711 | ||
4712 | ==> warn log_message = Accepted underscore from [$sender_host_address] | |
4713 | condition = ${if match{$sender_helo_name}{_}{yes}{no}} | |
4714 | ||
4715 | ||
4716 | Q0733: Is there any way to tell Exim not to lookup the IP address against any | |
4717 | DNS black list if the connection is over IPv6? | |
4718 | ||
4719 | A0733: Use this condition in your ACL: | |
4720 | ||
4721 | ==> condition = ${if match{${mask:$sender_host_address/0}}\ | |
4722 | {${mask:::0/0}}{no}{yes}} | |
4723 | ||
4724 | From Exim 4.23 onwards, this can be simplified to | |
4725 | ||
4726 | ==> condition = ${if isip6{$sender_host_address}{no}{yes}} | |
4727 | ||
4728 | ||
4729 | Q0734: How do MailScanner and Exiscan compare? What are the pros and cons? | |
4730 | ||
4731 | A0734: The big advantage of Exiscan is that it can reject messages at SMTP time | |
4732 | before you have accepted responsibility for them, which means you don't | |
4733 | have to deal with bouncing messages and thereby becoming a collateral | |
4734 | spammer. | |
4735 | ||
4736 | The big advantage of MailScanner is that it gives you much greater | |
4737 | control over the load on your machines. You configure it according to | |
4738 | the maximum processing capacity of your computer and it will not exceed | |
4739 | that; in fact because it deals with messages in batches the cost of | |
4740 | processing a message actually goes down slightly as the load increases, | |
4741 | because the per-batch costs are shared by more messages. | |
4742 | ||
4743 | With Exiscan, you have to rely on Exim's load protection mechanisms, | |
4744 | which basically means that you have to stop accepting messages when your | |
4745 | machine gets too loaded. This is bad if the machine happens to be an | |
4746 | SMTP smarthost. You therefore need more overcapacity with Exiscan than | |
4747 | with MailScanner. | |
4748 | ||
4749 | ||
4750 | Q0735: How can I block non-FQDNs in HELO/EHLOs? | |
4751 | ||
4752 | A0735: Many workstation clients send single-component names; take care that you | |
4753 | do not block legitimate mail. With that proviso, you can do it using | |
4754 | something like this in an ACL: | |
4755 | ||
4756 | ==> drop message = HELO doesn't look like a hostname | |
4757 | log_message = Not a hostname | |
4758 | condition = ${if match{$sender_helo_name} \ | |
4759 | {\N^[^.].*\.[^.]+$\N}{no}{yes}} | |
4760 | ||
4761 | This means: Drop the HELO unless it contains a dot somewhere in the HELO | |
4762 | string, but the string may not begin or end with a dot. Thus, the | |
4763 | imposed minimum length is 3 characters. | |
4764 | ||
4765 | The data for HELO/EHLO doesn't have to be a host name; it may | |
4766 | legitimately be an IP address literal instead. The above test succeeds | |
4767 | with an IPv4 address literal, but if you want also to accept IPv6 | |
4768 | address literals, you will have to modify the regular expression. | |
4769 | ||
4770 | ||
4771 | Q0736: Is it possible to tell exim to drop the connection after a server | |
4772 | attempts to send a message to a number of unknown users? | |
4773 | ||
4774 | A0736: Yes. Use \$rcpt_fail_count$\ and the \^drop^\ ACL command, as in this | |
4775 | example: | |
4776 | ||
4777 | ==> drop message = Too many unknown users | |
4778 | condition = ${if >{$rcpt_fail_count}{15}{yes}{no}} | |
4779 | ||
4780 | ||
4781 | Q0737: Is there some way to tell Exim not to consider 127.0.0.1 as a valid MX? | |
4782 | ||
4783 | A0737: See Q0319. | |
4784 | ||
4785 | ||
4786 | Q0738: How can I configure Exim to delay the SMTP connection if more than 10 | |
4787 | invalid recipients are received in one message? | |
4788 | ||
4789 | A0738: Put something like this in your RCPT ACL: | |
4790 | ||
4791 | ==> deny message = Max $rcpt_fail_count failed recipients allowed | |
4792 | condition = ${if >{$rcpt_fail_count}{10} {1}} | |
4793 | ! verify = recipient | |
4794 | delay = ${eval: $rcpt_fail_count * 10}s | |
4795 | log_message = $rcpt_fail_count failed recipient attempts | |
4796 | ||
4797 | This example increases the delay for each failed recipient. | |
4798 | ||
4799 | ||
4800 | Q0739: Does Exim support SPF? | |
4801 | ||
4802 | A0739: An Exim ACL can be used. See \?http://spf.pobox.com/downloads.html?\. | |
4803 | ||
4804 | ||
4805 | ||
4806 | 8. REWRITING ADDRESSES | |
4807 | ||
4808 | Q0801: How can I get Exim to strip the hostname from the sender's address? | |
4809 | ||
4810 | A0801: If you set up a rewriting rule in the following form: | |
4811 | ||
4812 | ==> *@*.your.domain $1@your.domain | |
4813 | ||
4814 | then Exim will rewrite all addresses in the envelope and the headers, | |
4815 | removing anything between \"@"\ and \"your.domain"\. This applies to all | |
4816 | messages that Exim processes. If you want to rewrite sender addresses | |
4817 | only, the the rule should be | |
4818 | ||
4819 | ==> *@*.your.domain $1@your.domain Ffrs | |
4820 | ||
4821 | This applies the rule only to the envelope sender address and to the | |
4822 | ::From::, ::Reply-to::, and ::Sender:: headers. | |
4823 | ||
4824 | ||
4825 | Q0802: I have Exim configured to remove the hostname portion of the domain on | |
4826 | outgoing mail, and yet the hostname is present when the mail gets | |
4827 | delivered. | |
4828 | ||
4829 | A0802: Check the DNS record for your domain. If the MX record points to a CNAME | |
4830 | record instead of to an A record, some MTAs (not Exim) are liable to | |
4831 | rewrite addresses, changing your domain name to its ``canonical'' form, | |
4832 | as obtained from the CNAME record. | |
4833 | ||
4834 | ||
4835 | Q0803: I want to rewrite local addresses in mail that goes to the outside | |
4836 | world, but not for messages that remain within the local intranet. | |
4837 | ||
4838 | A0803: You can use the \headers_rewrite\ option on a transport to do this. | |
4839 | The rewriting will then apply to just those copies of a message that | |
4840 | pass through the transport. The \return_path\ option can similarly be | |
4841 | used to rewrite the sender address. There is no way of rewriting | |
4842 | recipient addresses at transport time. However, as these are by | |
4843 | definition remote addresses, you probably don't want to rewrite them. | |
4844 | ||
4845 | You have to set up the configuration so that it uses different SMTP | |
4846 | transports for internal and external mail. If you are using a single | |
4847 | router in both cases, you could configure it like this: | |
4848 | ||
4849 | ==> dnslookup: | |
4850 | driver = dnslookup | |
4851 | transport = ${if match{$domain}{\N\.my\.domain$\N}{int_smtp}{ext_smtp}} | |
4852 | ||
4853 | This example uses the \%int_smtp%\ transport for domains ending in | |
4854 | \(.my.domain)\, and \%ext_smtp%\ for everything else. The \%ext_smtp%\ transport | |
4855 | could be something like this: | |
4856 | ||
4857 | ==> ext_smtp: | |
4858 | driver = smtp | |
4859 | headers_rewrite = *@*.my.domain \ | |
4860 | ${lookup{$1}cdb{/etc/$2/mail.handles.cdb}{$value}fail} | |
4861 | return_path = \ | |
4862 | ${if match{$return_path}{\N^([^@]+)@(.*)\.my\.domain$\N}\ | |
4863 | {\ | |
4864 | ${lookup{$1}cdb{/etc/$2/mail.handles.cdb}{$value}fail}\ | |
4865 | }\ | |
4866 | fail} | |
4867 | ||
4868 | This example uses a separate file of local-to-external address | |
4869 | translations for each domain. This is not the only possibility, of | |
4870 | course. The \headers_rewrite\ and \return_path\ options apply the same | |
4871 | rewriting to the header lines and the envelope sender address, | |
4872 | respectively. | |
4873 | ||
4874 | ||
4875 | Q0804: I'm using this rewriting rule to change login names into ``friendly'' | |
4876 | names, but if mail comes in for an upper case login name, it doesn't | |
4877 | get rewritten. | |
4878 | ||
4879 | ==> *@my.domain ${lookup{$1}dbm{/usr/lib/exim/longforms}\ | |
4880 | {$value}fail}@my.domain bcfrtFT | |
4881 | ||
4882 | The longforms database has entries of the form: | |
4883 | ||
4884 | ==> ano23: A.N.Other | |
4885 | ||
4886 | A0804: Replace \"$1"\ in your rule by \"${lc:$1}"\ to force the local part to lower | |
4887 | case before it is used as a lookup key. | |
4888 | ||
4889 | ||
4890 | Q0805: Is it possible to completely fail a message if the rewrite rules fail? | |
4891 | ||
4892 | A0805: It depends on what you mean by ``fail a message'' and what addresses you | |
4893 | are rewriting. If you are rewriting recipient addresses for your local | |
4894 | domain, you can do: | |
4895 | ||
4896 | ==> *@dom.ain ${lookup{$1}dbm{/wher/ever}{$value}{failaddr}} Ehq | |
4897 | ||
4898 | and in your alias file put something like | |
4899 | ||
4900 | ==> failaddr: :fail: Rewriting failed | |
4901 | ||
4902 | This fails a single recipient - others are processed independently. | |
4903 | ||
4904 | ||
4905 | Q0806: I'm using \$domain$\ as the key for a lookup in a rewriting rule, but its | |
4906 | contents are not being lowercased. Aren't domains supposed to be handled | |
4907 | caselessly? | |
4908 | ||
4909 | A0806: The value of \$domain$\ is the actual domain that appears in the address. | |
4910 | It could of course be lower cased, but I know that would cause some | |
4911 | unhappiness, because some people have mixed-case domain names which look | |
4912 | silly if the case is changed. Thus, one wants to preserve the case in | |
4913 | rewrites such as | |
4914 | ||
4915 | ==> *@*.TheRap.com something@$domain | |
4916 | ||
4917 | because ``therap'' doesn't look like two words. I know it seems trivial, | |
4918 | but it is important to some people - especially if by some unfortunate | |
4919 | accident the lowercased word is something indecent. | |
4920 | ||
4921 | You can trivally force lower casing by means of the \"${lc:"\ operator. | |
4922 | Instead of \"$domain"\ write \"${lc:$domain}"\. | |
4923 | ||
4924 | ||
4925 | Q0807: I want to rewrite local sender addresses depending on the domain of the | |
4926 | recipient. | |
4927 | ||
4928 | A0807: In general, this is not possible, because a message may have more than | |
4929 | one recipient and Exim keeps just a single copy of each message. It may | |
4930 | also deliver one copy of a message with several recipient addresses. | |
4931 | You can do an incomplete job by using a regular expression match in a | |
4932 | rewrite rule to test, for example, the contents of the ::To:: header. This | |
4933 | would work except in cases of multiple recipients. | |
4934 | ||
4935 | ||
4936 | ||
4937 | 9. HEADERS | |
4938 | ||
4939 | Q0901: I would like add some custom headers to selected outgoing mail based on | |
4940 | a specific domain and the subject line. | |
4941 | ||
4942 | A0901: To the remote_smtp transport, add something like | |
4943 | ||
4944 | ==> headers_add = ${if and{\ | |
4945 | {eq{$domain}{spec.dom}}\ | |
4946 | {matches{$h_subject:}{whatever}}}\ | |
4947 | {Content-Type: text/html; charset="us-ascii"} fail } | |
4948 | ||
4949 | This example shows a ::Content-Type:: header, but you can have anything you | |
4950 | like, and multiple headers can be inserted by using \"@\n"\ to separate them. | |
4951 | ||
4952 | ||
4953 | Q0902: Is it possible to have Exim add a header to only certain local parts of | |
4954 | outgoing mail? | |
4955 | ||
4956 | A0902: Only if you arrange for each such local part to receive its own private | |
4957 | copy of the mail. See \max_rcpt\ in the SMTP transport. If you set this | |
4958 | to 1, you could use conditions in an expansion string to add or not add | |
4959 | a header. | |
4960 | ||
4961 | ||
4962 | Q0903: How can I remove some part of the ::Received:: header? | |
4963 | ||
4964 | A0903: Set \received_header_text\. | |
4965 | ||
4966 | ||
4967 | Q0904: How I can insert the PGP header line using Exim filters? | |
4968 | ||
4969 | A0904: You can't insert headers in a user filter. A system filter can do so, | |
4970 | but the inserted lines then are included for all recipients. | |
4971 | ||
4972 | ||
4973 | Q0905: I know I can use a system filter to replace certain headers in messages, | |
4974 | but how can I add text to existing headers? I want to add [SPAM] to | |
4975 | the subject line of messages that appear to be spam. | |
4976 | ||
4977 | A0905: You can only do this in a round about way, using filter commands like | |
4978 | this: | |
4979 | ||
4980 | ==> headers add "New-Subject: SPAM: $h_subject:" | |
4981 | headers remove subject | |
4982 | neaders add "Subject: $h_new-subject:" | |
4983 | headers remove new-subject | |
4984 | ||
4985 | This trick works only in system filters, where the commands are obeyed | |
4986 | in order, and affect the master list of headers that apply to the whole | |
4987 | message. You cannot do this with the \headers_add\ and \headers_remove\ | |
4988 | options on drivers. | |
4989 | ||
4990 | ||
4991 | ||
4992 | 10. PERFORMANCE | |
4993 | ||
4994 | Q1001: I'm running a large mail server. Should I set \split_spool_directory\ to | |
4995 | improve performance? | |
4996 | ||
4997 | A1001: Splitting the spool directory has most benefit if there are times when | |
4998 | there are a large number of messages on the queue. If all mail is | |
4999 | delivered very quickly, and the queue is always less than, say, a few | |
5000 | hundred messages, there isn't any need to do this. With larger queues, | |
5001 | there is a definite performance benefit to splitting the spool. It shows | |
5002 | up earlier on some types of filing system, compared with others. | |
5003 | ||
5004 | Exim was not designed for handling large queues. If you are in an | |
5005 | enviroment where lots of messages remain on the queue for long periods | |
5006 | of time, consider implementing a back up host to which you pass these | |
5007 | messages, so that the main host's queue remains short. You can use | |
5008 | \fallback_hosts\ to do this, or a router that is conditional on | |
5009 | \$message_age$\. | |
5010 | ||
5011 | ||
5012 | Q1002: How well does Exim scale? | |
5013 | ||
5014 | A1002: Although the author did not specifically set out to write a high- | |
5015 | performance MTA, Exim does seem to be fairly efficient. The biggest | |
5016 | server at the University of Cambridge (a large Sun box) goes over | |
5017 | 100,000 deliveries per day on busy days (it has over 20,000 users). | |
5018 | There was a report of a mailing list exploder that sometimes handles | |
5019 | over 100,000 deliveries a day on a big Linux box, the record being | |
5020 | 177,000 deliveries (791MB in total). Up to 13,000 deliveries an hour | |
5021 | have been reported. | |
5022 | ||
5023 | These are quotes from some Exim users: | |
5024 | ||
5025 | "... Canada's largest internet provider, uses Exim on all of our mail | |
5026 | machines, and we're absolutely delighted with it. It brought life back | |
5027 | into one of our machines plagued with backlogs and high load averages. | |
5028 | Here's just an example of how much email our largest mail server | |
5029 | (quad SS1000) is seeing ... " [230,911 deliveries in a day: 4,475MB] | |
5030 | ||
5031 | "... Exim has to ... do gethostbyname()s and RBL lookups on all of the | |
5032 | incoming mail servers, and he runs from inetd (TCP Wrappers connected). | |
5033 | All the same, it seems to me that he runs as fast as lightning on our | |
5034 | SCO 5.0.4 box (1 Pentium 166) - far faster than MMDF which I (and many | |
5035 | customers) had before." | |
5036 | ||
5037 | "On a PII 400 with 128M of RAM running Linux 2.2.5, I have achieved | |
5038 | 36656 messages per hour (outgoing unique messages and recipients). For | |
5039 | about a 5 minute period, I was able to achieve an average of 30 messages | |
5040 | per second (that would be 108000 m/hour)! We are using: (options that | |
5041 | make a difference): | |
5042 | ||
5043 | ==> queue_only | |
5044 | split_spool_directory | |
5045 | queue_run_max = 1 | |
5046 | remote_max_parallel = 1 | |
5047 | ||
5048 | We have a cron job hat runs every five minutes that spawns 5 \"exim -q"\ if | |
5049 | there are less that 120 exim processes currently running. We found | |
5050 | that by manually controlling the concurrency of \"exim -q"\ processes | |
5051 | contending for the spool for \%remote_smtp%\ delivery that we gained | |
5052 | considerable performance - 10000 m/hour." | |
5053 | ||
5054 | ||
5055 | Q1003: We have a large password file. Can Exim use alternative lookups during | |
5056 | delivery to speed things up? | |
5057 | ||
5058 | A1003: If you are using FreeBSD, this problem should not arise, because it | |
5059 | automatically uses an indexed password file. In some other operating | |
5060 | systems you can arrange for this to happen too. On Linux, for example, | |
5061 | all you need to do is | |
5062 | ||
5063 | ==> # cd /var/db | |
5064 | # make | |
5065 | ||
5066 | and put \"db"\ before \"files"\ in any \(/etc/nsswitch.conf)\ lines you want to | |
5067 | use db for. | |
5068 | ||
5069 | On systems that do not include support for indexed password files, you | |
5070 | can build one yourself, and reference it from the Exim configuration. | |
5071 | For example, for routing to local mailboxes you could use this: | |
5072 | ||
5073 | ==> localuser: | |
5074 | driver = accept | |
5075 | condition = ${lookup{$local_part}cdb{/etc/passwd.cdb}{yes}{no}} | |
5076 | transport = local_delivery | |
5077 | user = ${extract{1}{:}{${lookup{$local_part}cdb{/etc/passwd.cdb}}} | |
5078 | ||
5079 | This assumes a cdb version of the password file. | |
5080 | ||
5081 | ||
5082 | Q1004: I just wondered if it might be helpful to put the hints database on a | |
5083 | RAM disk during regular operation. Did anybody try that yet? | |
5084 | ||
5085 | A1004: A user reported thus: ``I have found that this works great under Solaris. | |
5086 | Make a RAM disk partition and keep everything in the \(db)\ directory on | |
5087 | it. However, when I try the same thing on Linux, I don't see the same | |
5088 | boost. I think that Linux's file buffer cache works about the same. | |
5089 | Plus, this leave more room for processes to run.'' | |
5090 | ||
5091 | There have been other reports that Linux's delayed buffer write provides | |
5092 | better overall performance in general. | |
5093 | ||
5094 | Apparently there is support in the Solaris kernel for a delayed writing, | |
5095 | as in Linux, but Sun's server policy is to have it disabled so that you | |
5096 | don't lose so much if the server crashes. There is a program called | |
5097 | \^fastfs^\ to enable and disable this support. You have to download and | |
5098 | compile it yourself; find it by looking for \"fastfs.c"\ in a search | |
5099 | engine. Solaris performance is reported to be much improved, but you | |
5100 | should take care to understand the potential hazards. In particular, | |
5101 | \^fsck^\ may be unable to ``fix'' disks automatically after a crash. | |
5102 | ||
5103 | ||
5104 | Q1005: A lot of incoming mail is pushing up my system load too much, and there | |
5105 | are many Exim processes. How can I control this? | |
5106 | ||
5107 | A1005: Have you set any of the Exim configuration options that limit what it | |
5108 | does under high load? For example, queue_only_load, deliver_queue_load_max? | |
5109 | See the list in the section entitled \*Resource control*\ in the manual. | |
5110 | ||
5111 | It sounds like a lot of simultaneous incoming mail pushes your system | |
5112 | into uncontrolled overload. The multiple Exim processes are probably | |
5113 | just multiple incoming messages. You can use the \^exiwhat^\ utility to | |
5114 | confirm this. | |
5115 | ||
5116 | ||
5117 | ||
5118 | 11. MAJORDOMO | |
5119 | ||
5120 | Q1101: How do I set up Majordomo to work with Exim? | |
5121 | ||
5122 | A1101: Users have found several ways of setting up Exim for use with Majordomo. | |
5123 | One way has been documented at | |
5124 | \?http://www.averillpark.net/exim/majordomo.html?\. | |
5125 | ||
5126 | Somewhere in the Majordomo docs or FAQ it mentions using batchmail or | |
5127 | other additional programs to improve the performance of large lists. | |
5128 | They are not needed with Exim, and their use can actually make things | |
5129 | worse. However, it's a good idea to set \remote_max_parallel\ to a value | |
5130 | greater than 1 in the Exim configuration. | |
5131 | ||
5132 | ||
5133 | Q1102: I have set \$mailer$\ in \(majordomo.cf)\, but it still isn't setting the | |
5134 | sender correctly in the messages it sends. | |
5135 | ||
5136 | A1102: Make sure you have got the quoting correct in the \$mailer$\ setting. For | |
5137 | example, | |
5138 | ||
5139 | ==> $mailer = "$sendmail_command -oi -oee -f$sender\@lists.mydomain.de"; | |
5140 | ||
5141 | is not correct. It needs three backslashes, not one, and the $ at the | |
5142 | start of \$sender$\ has to be escaped with a backslash. | |
5143 | ||
5144 | ||
5145 | Q1103: I'm trying to set up majordomo, but I'm getting a wrong mode error | |
5146 | when I try to send it mail. | |
5147 | ||
5148 | A1103: Check the mode of \(/var/lib/majordomo/lists/lists.aliases)\ and compare it | |
5149 | with the setting of the \modemask\ option in the Majordomo aliases | |
5150 | router. This option specifies bits which must not be set for the alias | |
5151 | file, and it defaults to 022. | |
5152 | ||
5153 | ||
5154 | Q1104: I'm getting return code 9 from \(/home/majordomo/majordomo-1.94.4/wrapper)\ | |
5155 | when it is passed a message from Exim. | |
5156 | ||
5157 | A1104: A problem like this turned out to be the Perl version that came with | |
5158 | RedHat 5.2. Rebuilding Perl 5.005x solved it. | |
5159 | ||
5160 | ||
5161 | Q1105: Exim is complaining about an invalid command line when Majordomo tries | |
5162 | to send it a message for delivery. | |
5163 | ||
5164 | A1105: Take a look at your \(majordomo.cf)\ file, It should have something that | |
5165 | looks like | |
5166 | ||
5167 | ==> $sendmail_command = "/usr/lib/sendmail"; | |
5168 | ||
5169 | and another line like | |
5170 | ||
5171 | ==> $mailer = "$sendmail_command -oi -oee -f\$sender"; | |
5172 | ||
5173 | If you have modified \^resend^\ (one of the majordomo programs) to use | |
5174 | \$sendmail_command$\ instead of \$mailer$\ you will be calling Exim with no | |
5175 | command line arguments. | |
5176 | ||
5177 | ||
5178 | ||
5179 | 12. FETCHMAIL | |
5180 | ||
5181 | Q1201: When I run fetchmail, I get the error \*SMTP listener doesn't like | |
5182 | recipient address xxx@localhost*\. | |
5183 | ||
5184 | A1201: Make sure that //localhost// is recognized as a domain that is to be | |
5185 | delivered locally. If you are using the default Exim run time | |
5186 | configuration, you'll see a line near the top like this: | |
5187 | ||
5188 | ==> domainlist local_domains = @ | |
5189 | ||
5190 | Change it to | |
5191 | ||
5192 | ==> domainlist local_domains = @ : localhost | |
5193 | ||
5194 | ||
5195 | Q1202: I'm currently using Exim with fetchmail and I'd like to use the RBL on | |
5196 | Exim, but will it work? Do I need to configure fetchmail any particular | |
5197 | way? As far as Exim knows, all mail is coming from 127.0.0.1. Will it | |
5198 | check the source address against RBL? Or will it check the ::From:: header? | |
5199 | ||
5200 | A1202: It will check 127.0.0.1 (not very useful). The point of the RBL is to | |
5201 | keep messages from black-listed hosts out of your machine. If you are | |
5202 | using fetchmail, you have got the messages into your machine before you | |
5203 | approach Exim. That kind of defeats the purpose of the RBL. The right | |
5204 | way to do this would be for the host from which you fetch your mail to | |
5205 | do the RBL checking and insert some kind of warning header for you to | |
5206 | test, as Exim does if you run RBL checks in warning mode. | |
5207 | ||
5208 | ||
5209 | ||
5210 | 13. PERL | |
5211 | ||
5212 | Q1301: Exim built with Perl support exits with the error message \*./exim: can't | |
5213 | load library 'libperl.so'*\. | |
5214 | ||
5215 | A1301: If you are using BSDI, see Q9401. | |
5216 | ||
5217 | ||
5218 | Q1302: Exim built with Perl support exits with several error messages of the | |
5219 | form \*undefined reference to `PL_stack_sp'*\. | |
5220 | ||
5221 | A1302: This has been seen on FreeBSD systems that had two different versions of | |
5222 | Perl installed, the older with an \^a.out^\ library and the newer with an | |
5223 | ELF library. Ensure that the older package is removed. | |
5224 | ||
5225 | ||
5226 | ||
5227 | 14. DIAL-UP AND ISDN | |
5228 | ||
5229 | Q1401: When I'm not connected to the Internet, how can I arrange for mail to | |
5230 | other hosts on my local network to be delivered, while at the | |
5231 | same time mail to Internet hosts is queued without any delivery | |
5232 | attempts? | |
5233 | ||
5234 | A1401: Use the \queue_domains\ option to control which domains are held | |
5235 | on the queue for later delivery. For example, | |
5236 | ||
5237 | ==> queue_domains = ! *.localnet | |
5238 | ||
5239 | allows delivery to domains ending in \(.localnet)\, while queueing all the | |
5240 | others. | |
5241 | ||
5242 | ||
5243 | Q1402: I have a dial-up machine, and I use the \queue_smtp_domains\ option so | |
5244 | that remote mail only goes out when I do a queue run. However, any email | |
5245 | I send with an address \(anything@aol.com)\ is returned within about 15 | |
5246 | minutes saying \*retry time exceeded*\, and all addresses are affected. | |
5247 | ||
5248 | A1402: You should be using \queue_domains\ rather than \queue_smtp_domains\. | |
5249 | With the latter, Exim is trying to route the addresses, which involves a | |
5250 | DNS lookup. This is presumably timing out, causing a retry time to be | |
5251 | set for the domain, and somehow a valid lookup never happened before the | |
5252 | maximum retry time (default of 4 days) passed. Hence the bounce. The | |
5253 | fact that it is \(aol.com)\ is probably not relevant. You should probably | |
5254 | also be using \-qq-\ to do your queue run rather than \-q-\. | |
5255 | ||
5256 | ||
5257 | Q1403: How should Exim be configured when it is acting as a temporary storage | |
5258 | system for a domain on a dial-up host? | |
5259 | ||
5260 | A1403: Exim isn't really designed for this, but... The lowest-numbered MX | |
5261 | record for the domain should be pointing to the dial-up host. A higher | |
5262 | numbered MX record (lower priority) should point to the Exim server that | |
5263 | is acting as a temporary storage system. | |
5264 | ||
5265 | You should set a large retry time for the domain, so that Exim doesn't | |
5266 | keep trying to deliver when the host is offline. When the host comes | |
5267 | online, the waiting messages have to be kicked somehow. This can be done | |
5268 | by calling Exim with the \-R-\ option, or via the SMTP ETRN command. | |
5269 | ||
5270 | This works provided the number of messages is low. If you are handling | |
5271 | lots of mail, keeping messages waiting for their host to connect and | |
5272 | those that are having delivery problems to remote hosts all in the same | |
5273 | queue doesn't work so well. It is better in this case to get Exim to | |
5274 | deliver the mail for the dial-in hosts into some local files which then | |
5275 | get transmitted by other software when the host connects. One tool for | |
5276 | doing this can be found at \?http://cr.yp.to/serialmail.html?\. | |
5277 | ||
5278 | For further discussion, see section entitled \*Intermittently connected | |
5279 | hosts*\ in the manual, and also the section in the Exim book with the | |
5280 | same name. | |
5281 | ||
5282 | ||
5283 | Q1404: I have \queue_domains\ or \queue_smtp_domains\ set, and use \-qf-\ to | |
5284 | force delivery of waiting mail when I dial in. How can I arrange for any | |
5285 | new messages that arrive while I'm connected to be delivered immediately? | |
5286 | ||
5287 | A1404: Instead of \queue_domains\ or \queue_smtp_domains\, use the \queue_only_file\ | |
5288 | option. This causes messages to be queued if a particular file exists. | |
5289 | If you put the word ``smtp'' before the file name, the queueing applies | |
5290 | only to domains that are delivered by SMTP, thus not affecting local | |
5291 | deliveries: | |
5292 | ||
5293 | ==> queue_only_file = smtp/etc/present/when/not/connected | |
5294 | ||
5295 | Then, in the scripts which are run when you connect and disconnect, | |
5296 | arrange to remove the file after connection, and create it just before | |
5297 | disconnection. | |
5298 | ||
5299 | ||
5300 | Q1405: I have an ISDN connection and would like a way of running the queue | |
5301 | automatically when it is up. | |
5302 | ||
5303 | A1405: The following shell commands test for the interface being up and then | |
5304 | run the queue: | |
5305 | ||
5306 | ==> ifconfig ppp0 | fgrep UP >/dev/null | |
5307 | if [ $? -eq 0 ] ; then exim -q ; fi | |
5308 | ||
5309 | You could put these commands into a script which runs them at regular | |
5310 | intervals. You might want to use \-qq-\ instead of \-q-\. | |
5311 | ||
5312 | With Linux, the script \(/etc/ppp/ip-up)\ is run after a ISDN connection | |
5313 | or a more general PPP connection has been established. If you are using | |
5314 | Linux, you could put the call to Exim in that script. | |
5315 | ||
5316 | ||
5317 | Q1406: When I dial up to collect mail from my ISP, only the first 10 messages | |
5318 | get delivered immediately; the remainder just sit on the queue until a | |
5319 | queue runner process finds them. | |
5320 | ||
5321 | A1406: See Q0049. | |
5322 | ||
5323 | ||
5324 | Q1407: RFC 1985 specifies that the SMTP command \"ETRN host.domain"\ causes all | |
5325 | mail queued for that host, no matter what domain it's for, to be | |
5326 | delivered. Why doesn't Exim support this? | |
5327 | ||
5328 | A1407: Exim does not keep queues of mail for specific destinations. It just | |
5329 | keeps one pool of undelivered messages. What is more, once you start a | |
5330 | delivery of a message, it tries to deliver to all the addresses in the | |
5331 | message, not just the one you may be interested in. (Of course, this | |
5332 | doesn't usually do any harm.) | |
5333 | ||
5334 | The only way it could be done within Exim would be, for every message | |
5335 | on the queue, to go through the motions of routing each undelivered | |
5336 | address and see if that resulted in a delivery to the host of interest. | |
5337 | This could be extremely expensive (e.g. 1,000 messages on the queue, | |
5338 | only 1 for the given host). | |
5339 | ||
5340 | The bottom line is that Exim just wasn't designed for this kind of | |
5341 | operation, that is, holding messages for intermittently connected hosts. | |
5342 | The queueing arrangements are designed for handling delivery problems | |
5343 | that are not expected to be common. | |
5344 | ||
5345 | A better way to do this is to implement the required queues separately. | |
5346 | After all, keeping such mail on an active queue (where Exim will keep | |
5347 | trying to deliver) is silly. If there is a lot of mail for these hosts, | |
5348 | it also masks genuine delivery problems when you inspect the queue. | |
5349 | ||
5350 | Large ISPs who provide this kind of functionality do not usually leave | |
5351 | waiting mail on the MTA's queue. Instead, they get it delivered into | |
5352 | per-host directories, one message per file, in one of the special | |
5353 | formats (BSMTP, maildir, or mailstore) and when an ETRN arrives, it | |
5354 | kicks off some completely different program that establishes an SMTP | |
5355 | connection to the host and shovels the waiting mail down it. That seems | |
5356 | to me to be a much neater way of doing this. It means you can easily add | |
5357 | additional functionality such as archiving or throwing away uncollected | |
5358 | mail. | |
5359 | ||
5360 | One program that has this functionality is \^ssmtp^\, which can be | |
5361 | found in \?ftp://metalab.unc.edu/pub/Linux/system/mail/mta/?\. | |
5362 | Alternatively, sample configuration C037 demonstrates an elegant way of | |
5363 | using Exim itself to deliver the saved messages when the client issues | |
5364 | an ETRN. | |
5365 | ||
5366 | ||
5367 | Q1408: If email has been deferred to a member on a local mailing list | |
5368 | (implemented through forward files), and one of our ETRN clients is on | |
5369 | this mailing list, the \-R-\ won't flush the mailing list message for | |
5370 | that client. | |
5371 | ||
5372 | A1408: That is because \-R-\ matches only original recipient addresses, not those | |
5373 | produced as a result of expansion, because these are not (by default) | |
5374 | preserved from delivery to delivery. You can get round this by setting | |
5375 | \one_time\ on the forwarding router, but you are not allowed to have | |
5376 | expansions to pipes or files on routers that have \one_time\ set. | |
5377 | Therefore, you will have to have a separate router for mailing lists | |
5378 | (with \one_time\ set) to the one used for normal forward files that might | |
5379 | specify pipe or file deliveries. However, the problem will still be | |
5380 | present for any user who sets up a \(.forward)\ file to redirect to any of | |
5381 | the ETRN domains. See the last 3 paragraphs of Q1407 for a discussion of | |
5382 | an alternative approach. | |
5383 | ||
5384 | ||
5385 | Q1409: I would like to have a separate queue per domain for hosts which dial | |
5386 | in to collect their mail. | |
5387 | ||
5388 | A1409: Exim isn't really designed for this kind of operation. The only way to | |
5389 | do this would be to cause it to send those messages to a differently | |
5390 | configured version of Exim with its own spool area. This could be done | |
5391 | via a pipe or SMTP to a private port. The main Exim, listening on port | |
5392 | 25, would then be configured to run an appropriate command to prod one | |
5393 | of the others when it received ETRN, by means of the \smtp_etrn_command\ | |
5394 | option. | |
5395 | ||
5396 | You could probably manage this with a single Exim binary and a number of | |
5397 | different configuration files, passed to the special versions using the | |
5398 | \-C-\ option. For this application they could all run as \^exim^\, since no | |
5399 | root privilege would be needed. | |
5400 | ||
5401 | An alternative approach id to get Exim to deliver mail for such hosts | |
5402 | in batch SMTP format into some directory, and have the ETRN run | |
5403 | something to pass such messages to the dialled-in host. See also Q1403. | |
5404 | ||
5405 | ||
5406 | ||
5407 | 15. UUCP | |
5408 | ||
5409 | Q1501: The MX records for some UUCP domains point to my local host. How do I | |
5410 | get it to pass the messages on to UUCP? | |
5411 | ||
5412 | A1501: The simplest way is to create a file containing a list of domains, and | |
5413 | the hosts to which their messages should be sent, like this: | |
5414 | ||
5415 | ==> uucp1.domain.example: uucp1.host.example | |
5416 | uucp2.domain.example: uucp2.host.example | |
5417 | .... | |
5418 | ||
5419 | Then you can use a router like this: | |
5420 | ||
5421 | ==> uucp_router: | |
5422 | driver = accept | |
5423 | domains = lsearch;/etc/uucp/domains | |
5424 | transport = uucp_transport | |
5425 | ||
5426 | and a transport like this: | |
5427 | ||
5428 | ==> uucp_transport: | |
5429 | driver = pipe | |
5430 | user = nobody | |
5431 | command = /usr/local/bin/uux - -r $domain_data!rmail $local_part | |
5432 | return_fail_output | |
5433 | ||
5434 | The \$domain_data$\ variable retains the value that is looked up when | |
5435 | the \domains\ option in the router is matched. | |
5436 | ||
5437 | ||
5438 | Q1502: How can I get Exim to handle ``bang path'' addresses? | |
5439 | ||
5440 | A1502: In general, you can't (Exim is an Internet mailer and recognizes only | |
5441 | RFC 2822 domain-style addresses) but some restricted kinds of bang path | |
5442 | can be dealt with by appropriate rewriting - but please note the warning | |
5443 | below. | |
5444 | ||
5445 | Exim treats a bang path address as an unqualified local part, and so | |
5446 | will qualify it with your domain. A rule such as | |
5447 | ||
5448 | ==> \N^([^!]+)!(.+)@your\.domain$\N $2@$1 | |
5449 | ||
5450 | turns \(a!b@your.domain)\ into \(b@a)\. You can also use a repeating rule to | |
5451 | turn multi-component paths into the ``percent hack'' notation with a rule | |
5452 | such as | |
5453 | ||
5454 | ==> \N^([^!]+)!([^@%]+)(.+)$\N $2%$1$3 R | |
5455 | ||
5456 | which turns \(a!b@c)\ into \(b%a@c)\ and \(a!b!c@d)\ first into \(b!c%a@d)\ and then, | |
5457 | because of the R flag, into \(c%b%a@d)\. The R flag causes repetition up to | |
5458 | 10 times. | |
5459 | ||
5460 | \**Warning:**\ If you install a general rewriting rule like the above, you are | |
5461 | opening yourself up to the possibility of unwanted relaying. A host that | |
5462 | is not permitted to relay through your system could send a message with | |
5463 | an SMTP command line such as | |
5464 | ||
5465 | ==> RCPT TO:<victim-host!victim-user@your.domain> | |
5466 | ||
5467 | and this would be accepted because it is addressed to your domain. | |
5468 | However, the rewriting then converts the address, and the message does | |
5469 | in fact get relayed. One way round this, if all your bang path messages | |
5470 | are passed to Exim via SMTP, is to use the \"S"\ rewriting flag. This | |
5471 | applies a rewriting rule to incoming SMTP addresses as soon as they are | |
5472 | received, before checking for qualification, relaying, etc. So a rule | |
5473 | such as | |
5474 | ||
5475 | ==> \N^([^!]+)!(.+)$\N $2@$1 S | |
5476 | ||
5477 | rewrites simple two-component bang paths before the result is checked | |
5478 | for relaying. However, this does not rewrite addresses in the headers of | |
5479 | the message. | |
5480 | ||
5481 | ||
5482 | Q1503: We see something strange on our system in regards to mail coming in via | |
5483 | rmail from a UUCP link. The sender is being set to mailmaster instead of | |
5484 | the real sender, and a ::Sender:: header is being added to the message. | |
5485 | ||
5486 | A1503: If \(mailmaster)\ is the user that is running rmail, you need to include | |
5487 | that user in the \trusted_users\ configuration option. Only trusted users | |
5488 | are permitted to specify senders when mail is passed to Exim via the | |
5489 | command line. | |
5490 | ||
5491 | ||
5492 | ||
5493 | 16. MODIFYING MESSAGE BODIES | |
5494 | ||
5495 | Q1601: How can I add a disclaimer or an advertisement to a message? | |
5496 | ||
5497 | A1601: There are a number of technical and potential legal problems that arise | |
5498 | in connection with message modification. Some of them are listed below. | |
5499 | Some comment on the legal position of email disclaimers in English law | |
5500 | can be found at \?http://www.weblaw.co.uk/artemail.htm?\. | |
5501 | ||
5502 | See also \?http://www.goldmark.org/jeff/stupid-disclaimers/?\. There is | |
5503 | some discussion about the problems of actually adding disclaimers in | |
5504 | \?http://www.goldmark.org/jeff/stupid-disclaimers/apply.html?\. | |
5505 | ||
5506 | In many cases, email disclaimers will make your company look ridiculous, | |
5507 | at the very least. At worst, they may interfere with the normal | |
5508 | processing of mail. | |
5509 | ||
5510 | If, despite these considerations, you still want to modify messages, you | |
5511 | can do so using Exim, but not directly in Exim itself. It is not the job | |
5512 | of an MTA to modify messages, something that requires understanding of | |
5513 | their content and format. | |
5514 | ||
5515 | Exim provides a hook called a ``transport filter'' that lets you pass | |
5516 | any outgoing message through a program or script of your choice. It | |
5517 | is the job of this script to make any changes to the message that you | |
5518 | require. By this means, you have full control over what changes are | |
5519 | made, and Exim does not need to know anything about message bodies. | |
5520 | However, using a transport filter requires additional resources, and may | |
5521 | slow down mail delivery. | |
5522 | ||
5523 | You can use Exim's routers to arrange for those messages that you want | |
5524 | to modify to be delivered via a transport filter. For example, suppose | |
5525 | you want to do this for messages from addresses in your domain that are | |
5526 | being delivered to a remote host. First you need to set up a special | |
5527 | \%smtp%\ transport that uses a filter, like this: | |
5528 | ||
5529 | ==> remote_smtp_filter: | |
5530 | driver = smtp | |
5531 | transport_filter = /your/filter/command | |
5532 | ||
5533 | Then you need to modify the \%dnslookup%\ router to use this transport | |
5534 | when the conditions are right: | |
5535 | ||
5536 | ==> dnslookup: | |
5537 | driver = dnslookup | |
5538 | domains = ! +local_domains | |
5539 | transport = ${if eq {$sender_address_domain}{your.domain}\ | |
5540 | {remote_smtp_filter}{remote_smtp}} | |
5541 | ignore_target_hosts = 127.0.0.0/8 | |
5542 | no_more | |
5543 | ||
5544 | This is the standard \%dnslookup%\ router, but with a modified setting of | |
5545 | the \transport\ option. When the sender address is in your domain, it | |
5546 | routes to the special transport instead of the standard one. | |
5547 | ||
5548 | The entire message is passed to your filter command on its standard | |
5549 | input. It must write the modified version to the standard output, taking | |
5550 | care not to break the RFC 2822 syntax. The command is run as the Exim | |
5551 | user. | |
5552 | ||
5553 | There are a number of potential problems in doing this kind of | |
5554 | modification in an MTA. Many people believe that to attempt is it wrong, | |
5555 | because: | |
5556 | ||
5557 | 1. It breaks digital signatures, which are becoming legally binding | |
5558 | in some countries. It may well also break encryption. | |
5559 | ||
5560 | 2. It is likely to break MIME encoding, that is, it is likely to wreck | |
5561 | attachments, unless great care is taken. And what about the case of a | |
5562 | message containing only binary MIME parts? | |
5563 | ||
5564 | 3. It is illegal under German and Dutch law to change the body of | |
5565 | a mail message in transit. It might potentially be illegal in | |
5566 | the UK under European law. This consideration applies to ISPs and | |
5567 | other ``common carriers''. It would presumably not apply in a corporate | |
5568 | environment where modification was done only to messages originating | |
5569 | from the employees, before they left the company's network. It might | |
5570 | also not apply if the senders have explicitly given their consent | |
5571 | (e.g. agreed to have advertisements added to their incoming mail). | |
5572 | ||
5573 | 4. Since the delivered message body was produced by the MTA (not the | |
5574 | originator, because it was modified), the MTA operator could | |
5575 | potentially be sued for any content. This again applies to `common | |
5576 | carrier' MTAs. It's interesting that adding a disclaimer of liability | |
5577 | could be making you liable for the message, but this case seems | |
5578 | more likely to involve adding advertisements than disclaimers. After | |
5579 | all, no postal service in the world opens all the mail it carries to | |
5580 | add disclaimers. | |
5581 | ||
5582 | 5. Some mail clients (old versions of MS outlook) crash if the message | |
5583 | body of an incoming MIME message has been tampered with. | |
5584 | ||
5585 | There are also potential problems that could arise if a scheme to add | |
5586 | disclaimers goes wrong for some messages: | |
5587 | ||
5588 | 1. False negatives: `Ah, this guy usually says he does not represent | |
5589 | their views, but in this message he doesn't have the disclaimer'. | |
5590 | ||
5591 | 2. False positives: `This official announcement does not represent our | |
5592 | views, oh no'. | |
5593 | ||
5594 | An alternative approach to the disclaimer problem would be to insist | |
5595 | that all relevant messages have the disclaimer appended by the MUA. The | |
5596 | MTA should refuse to accept any that do not. Again, however, the MTA | |
5597 | must understand the format of messages in order to do this. Simply | |
5598 | checking for appropriate wording at the end of the body is not good | |
5599 | enough. It would probably be necessary to run a Perl script from within | |
5600 | an Exim system filter, or write a \^^local_scan()^^\ function in order | |
5601 | to adopt this approach. | |
5602 | ||
5603 | Finally, it's a trivial matter to add customized headers of the sort: | |
5604 | ||
5605 | ==> X-Disclaimer: This is a standard disclaimer that says that the views | |
5606 | X-Disclaimer: contained within this message are somebody else's. | |
5607 | ||
5608 | which is a much easier alternative to modifying message bodies. | |
5609 | ||
5610 | ||
5611 | Q1602: How can I remove attachments from messages? | |
5612 | ||
5613 | A1602: The answer to this is essentially the same as for Q1601. | |
5614 | ||
5615 | ||
5616 | ||
5617 | 17. ENCRYPTION (TLS/SSL) | |
5618 | ||
5619 | Q1701: I am trying to set up an Exim server that uses a self-signed certificate | |
5620 | to enable my clients to use TLS. However, clients other than Exim | |
5621 | refuse to accept this certificate. What's wrong? | |
5622 | ||
5623 | A1701: It seems that some clients require that the certificate presented by | |
5624 | the server be a user (also called ``leaf'' or ``site'') certificate, and not | |
5625 | a self-signed certificate. In this situation, the self-signed | |
5626 | certificate must be installed on the client as a trusted root | |
5627 | \*certification authority*\ (CA), and the certificate used by the server | |
5628 | must be a user certificate signed with that self-signed certificate. | |
5629 | ||
5630 | For information on creating self-signed CA certificates and using them | |
5631 | to sign user certificates, see the \*General implementation overview*\ | |
5632 | chapter of the Open-source PKI book, available online at | |
5633 | \?http://ospkibook.sourceforge.net/?\. Here is a quick overview. First, | |
5634 | read this message: | |
5635 | ||
5636 | \?http://www.FreeBSD.org/cgi/mid.cgi?id=3C3F3A93.C1ECF9B0%40mindspring.com?\ | |
5637 | ||
5638 | Then, follow the instructions found on these two (consecutive) pages: | |
5639 | ||
5640 | \?http://ospkibook.sourceforge.net/docs/OSPKI-2.4.6/OSPKI/initialisation.htm?\ | |
5641 | \?http://ospkibook.sourceforge.net/docs/OSPKI-2.4.6/OSPKI/keygensign.htm?\ | |
5642 | ||
5643 | Two points on the PKI Book literature: | |
5644 | ||
5645 | (1) It's assumed that it's okay to use a passphrase-protected key to | |
5646 | encrypt the user/site/leaf certificate. If this isn't acceptable, | |
5647 | you seem to be able to strip out the passphrase as follows: | |
5648 | ||
5649 | ==> openssl rsa -in user.key -our user.key.new | |
5650 | mv user.key.new | |
5651 | ||
5652 | This should be done immediately after \(user.key)\ is created. | |
5653 | ||
5654 | (2) The \*sign.sh*\ script is available in the \*mod_ssl*\ distribution, | |
5655 | available at \?http://www.modssl.org/source/?\. | |
5656 | ||
5657 | Having followed the instructions, you end up with the following files: | |
5658 | ||
5659 | (a) \(ca.crt)\ | |
5660 | ||
5661 | This file should be installed into the client software as a trusted | |
5662 | root certification authority. In Windows XP, this can be done as follows: | |
5663 | ||
5664 | \#\#Call the file \(ca_cert.cer)\ | |
5665 | [[br]] | |
5666 | \#\#Double-click on the file | |
5667 | [[br]] | |
5668 | \#\#"Install Certificate"; | |
5669 | [[br]] | |
5670 | \#\#"Next" | |
5671 | [[br]] | |
5672 | \#\#"Place all certificates in the following store" | |
5673 | [[br]] | |
5674 | \#\#"Browse..." | |
5675 | [[br]] | |
5676 | \#\#"Trusted Root Certification Authorities" | |
5677 | [[br]] | |
5678 | \#\#"OK" | |
5679 | [[br]] | |
5680 | \#\#"Next" | |
5681 | [[br]] | |
5682 | \#\#"Finish" | |
5683 | [[br]] | |
5684 | \#\#"Yes" | |
5685 | [[br]] | |
5686 | \#\#"OK" | |
5687 | ||
5688 | (b) \(user.crt)\ and \(user.key)\ | |
5689 | ||
5690 | These files should be installed into the server software. In Exim, this | |
5691 | can be done by adding these lines to the configuration file: | |
5692 | ||
5693 | ==> tls_certificate = /usr/local/etc/exim/tls_cert | |
5694 | tls_privatekey = /usr/local/etc/exim/tls_key | |
5695 | ||
5696 | Then install \(user.crt)\ and \(user.key)\ under the names \(tls_cert)\ | |
5697 | and \(tls_key)\ in the appropriate directory. | |
5698 | ||
5699 | ||
5700 | Q1702: How can I arrange for Exim to advertise support for SMTP authentication | |
5701 | only when the session is encrypted? | |
5702 | ||
5703 | A1702: Use this setting: | |
5704 | ||
5705 | ==> auth_advertise_hosts = ${if eq{$tls_cipher}{}{}{*}} | |
5706 | ||
5707 | ||
5708 | Q1703: I have some legacy clients that don't use STARTTLS, but which expect to | |
5709 | negotiate a TLS session automatically on connection to the ssmtp port | |
5710 | (465). Can Exim handle this? | |
5711 | ||
5712 | A1703: The \-tls-on-connect-\ option is available to handle this. You need to | |
5713 | run two instances of an Exim listener, listening on different ports, one | |
5714 | of which is started with \-tls-on-connect-\. You can either use two | |
5715 | daemons, or a single daemon, with the other listenever using \^inetd^\. | |
5716 | For example, here are commands to start two daemons: | |
5717 | ||
5718 | ==> exim -bd -q15m | |
5719 | exim -bd -oX '[0.0.0.0]::465' -tls-on-connect | |
5720 | ||
5721 | The first is a ``normal'' daemon; the second listens on port 465 and | |
5722 | expects to negotiate a TLS session at the start of each connection. | |
5723 | ||
5724 | ||
5725 | Q1704: When my Outlook Express 6.0 client sends a STARTTLS command to begin a | |
5726 | TLS session, Exim doesn't seem to receive it. | |
5727 | ||
5728 | A1704: See Q0059. | |
5729 | ||
5730 | ||
5731 | Q1705: I have listed some hosts in \tls_try_verify_hosts\, but when they | |
5732 | connect, no data appears in \$tls_peerdn$\. | |
5733 | ||
5734 | A1705: This means that the clients have not sent certificates when asked by | |
5735 | the server to do so. If the clients are running Exim, check that | |
5736 | \tls_certificate\ is correctly set in their \%smtp%\ transports. Note | |
5737 | that this value is not automatically inherited from the global | |
5738 | \tls_certificate\ option. | |
5739 | ||
5740 | ||
5741 | Q1706: I have listed some hosts in \tls_verify_hosts\ and provided them with | |
5742 | certificates, but their connections are always rejected. | |
5743 | ||
5744 | A1706: Make sure that the server file containing the expected certificates | |
5745 | (defined by \tls_verify_certificates\) is readable by the Exim user. | |
5746 | See also the answer to Q1705. | |
5747 | ||
5748 | ||
5749 | Q1707: I am trying to use TLS with Evolution as a client, and keep seeing this | |
5750 | error: \*SMTP protocol violation: synchronization error (next input | |
5751 | sent too soon): rejected "\200F^A^C".*\ What does it mean? | |
5752 | ||
5753 | A1707: See Q0086 for a general explanation of the error. In this case, it | |
5754 | probably means that Evolution is trying to negotiate a TLS session | |
5755 | immediately it connects, without first using the STARTTLS command. This | |
5756 | was an older way of starting up TLS, before STARTTLS was defined. You | |
5757 | will have to run a separate instance of Exim using the | |
5758 | \-tls-on-connect-\ command line option to cater for this usage, and | |
5759 | listening on a different port. For example: | |
5760 | ||
5761 | ==> exim -bd -oX 465 -tls-on-connect | |
5762 | ||
5763 | 465 is the ``smtps'' port which is an unofficial standard for this kind | |
5764 | of SMTP server. | |
5765 | ||
5766 | ||
5767 | Q1708: I trying to use TLS with Outlook as a client on a box that is running | |
5768 | Norton Antivirus, but all my email is being rejected with \*Unsupported | |
5769 | command*\ errors. Why? | |
5770 | ||
5771 | A1708: Norton Antivirus does not support TLS or AUTH. It puts a broken SMTP | |
5772 | proxy between you and the Exim server. You need to turn off outbound | |
5773 | scanning of email. | |
5774 | ||
5775 | ||
5776 | ||
5777 | 20. MILLENNIUM | |
5778 | ||
5779 | Q2000: Are there any Y2K issues with Exim? | |
5780 | ||
5781 | A2000: The author of Exim believes that it is Y2K-compliant, as long as the | |
5782 | underlying operating system and C library are. Exim does not parse dates | |
5783 | or times at all. Internally, it makes some use of binary timestamps in | |
5784 | Unix format (number of seconds since 1-Jan-1970) and uses C library | |
5785 | services to convert these to printing forms (e.g. for logging). The | |
5786 | printing forms all use 4-digit years. Some people have tried various | |
5787 | tests. No problems have been reported, but details of what tests have | |
5788 | been done are not available. | |
5789 | ||
5790 | Well, it's now November 2001, and no Y2K problems have been reported, so | |
5791 | it looks like I was right. This entry is retained as historical | |
5792 | nostalgia. | |
5793 | ||
5794 | ||
5795 | ||
5796 | 50. MISCELLANEOUS | |
5797 | ||
5798 | Q5001: How can I arrange to allow a limited set of users to perform a limited | |
5799 | set of Exim administration functions? I don't want to put them all in | |
5800 | the //exim// group. | |
5801 | ||
5802 | A5001: See \?http://www.chiark.greenend.org.uk/~ian/userv/?\. Using \^userv^\ you can | |
5803 | arrange (for example) for certain users to be able to invoke \^mailq^\ or | |
5804 | \^runq^\ or other preset commands as \^exim^\ (or any other user, as configured) | |
5805 | with only \^userv^\ configuration. If you want to check the particular Exim | |
5806 | options available you can easily do it with shell or Perl scripts and | |
5807 | \^userv^\ configuration, and provided you know how to do argument | |
5808 | ``unparsing'' properly in shell or Perl it will be secure. | |
5809 | ||
5810 | ||
5811 | Q5002: I want to ``tail'' the Exim log, but I have a number of other logs I also | |
5812 | want to ``tail'', and the number of tailing windows is getting to be a | |
5813 | nuisance. | |
5814 | ||
5815 | A5002: Look for a program called \^xtail^\ (despite its name, it's not an | |
5816 | X-windows application). It allows you to do multiple tails, even of | |
5817 | entire directories. | |
5818 | ||
5819 | Alternately, get the GNU version of \^tail^\, from the GNU textutils | |
5820 | package (\?ftp://ftp.gnu.org/gnu/textutils/?\). GNU tail lets you run | |
5821 | \"tail -f\" on multiple files at the same time, although it doesn't work | |
5822 | on entire directories like \^xtail^\ can. If you are running Linux, you | |
5823 | probably already have a version of GNU \^tail^\ that can follow multiple | |
5824 | files. | |
5825 | ||
5826 | ||
5827 | Q5003: How can I persuade Exim to accept ETRN commands without the leading | |
5828 | # character? | |
5829 | ||
5830 | A5003: Set the option | |
5831 | ||
5832 | ==> smtp_etrn_command = /usr/lib/sendmail -R $domain | |
5833 | ||
5834 | This causes Exim to run that command, with \$domain$\ replaced by the | |
5835 | argument of ETRN. The default action of Exim is to require the # sign | |
5836 | in order to be RFC-compliant, and to run the equivalent of | |
5837 | ||
5838 | ==> smtp_etrn_command = /usr/lib/sendmail -R ${substr_1:$domain} | |
5839 | ||
5840 | which uses the argument without the leading # as the value for the \-R-\ | |
5841 | option. You aren't restricted to running Exim with the \-R-\ option, of | |
5842 | course. You can specify any command you like, with any number of | |
5843 | arguments. In particular, you can pass over the IP address of the caller | |
5844 | via \$sender_host_address$\. However, if you make use of expansion strings | |
5845 | in the arguments, each one must be entirely contained in a single | |
5846 | argument. For example, if you want to remove the first character of the | |
5847 | ETRN argument when it is @ or #, you could use | |
5848 | ||
5849 | ==> smtp_etrn_command = "/usr/lib/sendmail -R \ | |
5850 | \"${if match {$domain}{^[@#]}{${substr_1:$domain}}{$domain}}\"" | |
5851 | ||
5852 | The internal quotes are necessary because of the white space inside the | |
5853 | expansion string. | |
5854 | ||
5855 | ||
5856 | Q5004: I've recently noticed that emails I send with a ::Bcc:: line are being | |
5857 | delivered to their final destination with the ::Bcc:: line still present. | |
5858 | ||
5859 | A5004: Exim removes ::Bcc:: lines only if you call it with the \-t-\ option (i.e. | |
5860 | when it is acting partly as an MUA). It does not remove ::Bcc:: lines that | |
5861 | are present in incoming SMTP mail or command-line mail that does not | |
5862 | use \-t-\. Indeed, it should not remove them, because only the | |
5863 | initiating software (i.e. the MUA) can tell what to do with ::Bcc:: | |
5864 | lines; any MTA software has to leave them alone. This is what RFC 2822 | |
5865 | has to say about ::Bcc:: | |
5866 | ||
5867 | \*The ::Bcc:: field (where the ``Bcc'' means ``Blind Carbon Copy'') contains | |
5868 | addresses of recipients of the message whose addresses are not to be | |
5869 | revealed to other recipients of the message. There are three ways in | |
5870 | which the ::Bcc:: field is used. In the first case, when a message | |
5871 | containing a ::Bcc:: field is prepared to be sent, the ::Bcc:: line is | |
5872 | removed even though all of the recipients (including those specified | |
5873 | in the ::Bcc:: field) are sent a copy of the message. In the second | |
5874 | case, recipients specified in the ::To:: and ::Cc:: lines each are sent | |
5875 | a copy of the message with the ::Bcc:: line removed as above, but the | |
5876 | recipients on the ::Bcc:: line get a separate copy of the message | |
5877 | containing a ::Bcc:: line. (When there are multiple recipient | |
5878 | addresses in the ::Bcc:: field, some implementations actually send a | |
5879 | separate copy of the message to each recipient with a ::Bcc:: | |
5880 | containing only the address of that particular recipient.) Finally, | |
5881 | since a ::Bcc:: field may contain no addresses, a ::Bcc:: field can be | |
5882 | sent without any addresses indicating to the recipients that blind | |
5883 | copies were sent to someone. Which method to use with ::Bcc:: fields | |
5884 | is implementation dependent, but refer to the ``Security | |
5885 | Considerations'' section of this document for a discussion of each.*\ | |
5886 | ||
5887 | ||
5888 | Q5005: I used \^gv^\ 3.5.8 (\^ghostview^\) to try printing \(spec.ps)\. After every | |
5889 | printed page, the printer ejects a blank sheet. Is this something to do | |
5890 | with using ``letter'' rather than A4 paper? | |
5891 | ||
5892 | A5005: This seems to be an effect of using \^ghostview^\. Although the PostScript | |
5893 | is generated for A4 pages, the size of the page images is such that they | |
5894 | should fit on a letter page (they are shorter than would normally be | |
5895 | used on A4 paper). If the PostScript file is sent directly to a | |
5896 | PostScript printer, there is no problem. An alternative is to get hold | |
5897 | of the \^psutils^\ toolset, which is available from | |
5898 | \?ftp://ftp.dcs.ed.ac.uk/pub/psutils/psutils.tar.gz?\. | |
5899 | It contains utilities for extracting pages (which can be useful for | |
5900 | double-sided printing) and for resizing pages. If you resize from A4 to | |
5901 | letter the text shrinks a bit, but should then be printable via | |
5902 | \^ghostview^\. | |
5903 | ||
5904 | ||
5905 | Q5006: Why aren't there any man pages for Exim? I don't always carry my printed | |
5906 | documentation. | |
5907 | ||
5908 | A5006: A single man page which lists the command line options is provided in | |
5909 | file \(doc/exim.8)\ in the Exim distribution. Several other forms of | |
5910 | online documentation are available. As well as plain ASCII text, the | |
5911 | there are two forms - Texinfo and HTML - which have a certain amount of | |
5912 | built-in indexing for ease of finding your way around. There are no man | |
5913 | pages apart from the command line one because the author of Exim hasn't | |
5914 | the time (or desire :-) to maintain yet another documentation format. | |
5915 | Besides, it is hard to know how to split the Exim manual up. | |
5916 | ||
5917 | ||
5918 | Q5007: When I send a message using the \-t-\ command line option, Exim sends only | |
5919 | to the addresses within the message, not to those on the command line. | |
5920 | ||
5921 | A5007: There seems to be some confusion in the Sendmail community about the | |
5922 | interpretation of recipient addresses on the command line if the \-t-\ | |
5923 | option is used. Some versions do one thing, and some another. Here is an | |
5924 | except from one version of the Sendmail documentation for \-t-\: | |
5925 | ||
5926 | \*Read message for recipients. ::To::, ::Cc::, and ::Bcc:: lines will | |
5927 | be scanned for recipient addresses. The ::Bcc:: line will be | |
5928 | deleted before transmission. Any addresses in the argument | |
5929 | list will be suppressed, that is, they will not receive | |
5930 | copies even if listed in the message header.*\ | |
5931 | ||
5932 | By default Exim follows this specification, and interprets addresses on | |
5933 | the command line as addresses not to send to. You can set | |
5934 | ||
5935 | ==> extract_addresses_remove_arguments = false | |
5936 | ||
5937 | to change this behaviour so that command line addresses are added to the | |
5938 | addresses that are taken from the header lines. | |
5939 | ||
5940 | ||
5941 | Q5008: If I set up a domain list to contain //*customer.com//, it matches | |
5942 | //customer.com// and //abc.customer.com// as required, but it also matches | |
5943 | //noncustomer.com//, which is wrong. How can I get round this? | |
5944 | ||
5945 | A5008: You have to specify two entries in the list: | |
5946 | ||
5947 | ==> customer.com : *.customer.com | |
5948 | ||
5949 | because * in a domain list matches any characters, including \"."\ and | |
5950 | including a null sequence. | |
5951 | ||
5952 | ||
5953 | Q5009: I want to match all domains of the form //*.oyoy.org// but want a few | |
5954 | exceptions. For instance I don't want //foo.oyoy.org// or //bar.oyoy.org// to be | |
5955 | included. What is the best way to do this? | |
5956 | ||
5957 | A5009: Use negative items in the domain list, like this: | |
5958 | ||
5959 | ==> domainlist local_domains = !foo.oyoy.org : !bar.oyoy.org : *.oyoy.org | |
5960 | ||
5961 | If there are many exceptions, you can use a lookup instead of listing | |
5962 | them all inline. If there are a number of exceptions that match a | |
5963 | particular pattern, you could use a regular expression. | |
5964 | ||
5965 | ||
5966 | Q5010: I can't seem to find a pre-built version of Exim anywhere. The machine | |
5967 | is a Sparc 5 running Solaris 2.6. | |
5968 | ||
5969 | A5010: The primary distribution is source-only. However, some people have built | |
5970 | and distributed RPMs and debs for Linux systems, and ports for FreeBSD. | |
5971 | I haven't heard of anyone doing this for Solaris. The main problem with | |
5972 | binary distributions is that there are a number of build-time options, | |
5973 | requiring the answers to questions like: | |
5974 | ||
5975 | . Which DBM library do you have? (On Solaris probably ndbm, but no easy | |
5976 | default on some other systems.) | |
5977 | ||
5978 | . Which uid/gid do you want to use for Exim? | |
5979 | ||
5980 | . Where do you want the configuration file to be? (Many different | |
5981 | answers, even on the same OS, depending on local policy.) | |
5982 | ||
5983 | . Ditto for the binaries. | |
5984 | ||
5985 | . Which optional bits of Exim do you want to include? | |
5986 | ||
5987 | ||
5988 | Q5011: Is there a version of Exim available that runs under Windows? | |
5989 | ||
5990 | A5011: A long time ago somebody took a copy of the Exim source with the aim of | |
5991 | trying to port it to Windows NT. However, I never heard anything more. | |
5992 | However, current versions of Exim can be made to run under Cygwin. | |
5993 | ||
5994 | ||
5995 | Q5012: Does Exim support Delivery Status Notification (DSN), Message Status | |
5996 | Notification (MSN), or any other form of delivery acknowledgement? | |
5997 | ||
5998 | A5012: See Q0607. | |
5999 | ||
6000 | ||
6001 | Q5013: What does ``Exim'' stand for? | |
6002 | ||
6003 | A5013: Originally, it was ``EXperimental Internet Mailer'', which was the best I | |
6004 | could come up with when I was starting out. At that point it was | |
6005 | experimental - I wanted to see if the ideas I had for extending Smail's | |
6006 | approach actually worked. Then somebody discovered about it and wanted | |
6007 | to start using it, and told other people about it... | |
6008 | ||
6009 | ||
6010 | Q5014: Although I haven't set \check_spool_space\, Exim is still checking the | |
6011 | amount of space on the spool for incoming SMTP messages that use the | |
6012 | SIZE option. Can I suppress this? | |
6013 | ||
6014 | A5014: The RFC for the SIZE option says: | |
6015 | ||
6016 | \*If the server currently lacks sufficient resources to accept a | |
6017 | message of the indicated size, but may be able to accept the | |
6018 | message at a later time, it responds with code ``452 | |
6019 | insufficient system storage''.*\ | |
6020 | ||
6021 | and that is what Exim is trying to implement. This is entirely | |
6022 | independent from \check_spool_space\, which says \*don't accept any mail | |
6023 | if there is less than so much space in the spool partition*\, though the | |
6024 | code is optimised to do both checks at the same time if required. | |
6025 | However, you can suppress the SIZE check if you want to, by unsetting | |
6026 | \smtp_check_spool_space\. | |
6027 | ||
6028 | ||
6029 | Q5015: I just noticed log entries that start off \"<= <>"\. Am I correct in | |
6030 | assuming that the \"<>"\ indicates that the envelope did not contain any | |
6031 | ``From'' data? | |
6032 | ||
6033 | A5015: Yes. This indicates a delivery failure report (aka a ``bounce message''), | |
6034 | as specified in RFC 2821. The reason for using empty sender addresses is | |
6035 | to identify bounce messages so that they themselves do not cause further | |
6036 | bounces. Empty senders are also used for other kinds of report which | |
6037 | should not themselves cause the generation of bounce messages. For | |
6038 | example, Exim uses them when sending out warnings about delivery delays. | |
6039 | ||
6040 | ||
6041 | Q5016: I've received a message which does not have my address in the ::To:: | |
6042 | line. It is a spam message with the same address in both the ::From:: and | |
6043 | the ::To:: headers. How can this happen, and why doesn't Exim reject it? | |
6044 | ||
6045 | A5016: There is an important distinction between the ``envelope'' from and to and | |
6046 | the ``header'' from and to. The former are sometimes called the ``sender'' | |
6047 | and ``recipient''. An email message needs an ``envelope'' for the same | |
6048 | reason that paper mail does - the envelope tells the delivery mechanism | |
6049 | what to do with this copy of the message, whereas the ::To:: header lists | |
6050 | all the recipients, including those who have been sent different copies | |
6051 | of the message because their mailbox is on some other host. | |
6052 | ||
6053 | An MTA such as Exim works entirely with the ``envelope'' addresses, not | |
6054 | with those in the header lines. Don't try to block mail where envelope | |
6055 | from and the header from differ. There are common legitimate cases where | |
6056 | this happens, for example, messages forwarded from mailing lists and | |
6057 | delivery failure reports. | |
6058 | ||
6059 | ||
6060 | Q5017: Can (or will) Exim ever handle a message delivery purely in memory, | |
6061 | that is, it is handled without it ever hitting the disk? | |
6062 | ||
6063 | A5017: It doesn't, and never will. Accepting and delivering a message are two | |
6064 | entirely separate, independent processes, which communicate only by | |
6065 | writing/reading the message on the disk. | |
6066 | ||
6067 | ||
6068 | Q5018: If I am using dbm files for data that Exim reads, can I rebuild them | |
6069 | on the fly, or do I need to restart Exim every time I make a change? | |
6070 | ||
6071 | A5018: Exim re-reads the file every time it consults it, so if you are using a | |
6072 | cdb or a DBM library that uses just a single file (i.e. not ndbm), | |
6073 | you can just build the new file with a temporary file name, and use | |
6074 | \^mv^\ to rename it into the correct place on the fly. If there are two | |
6075 | files to rename, there is a window of time during which the DBM database | |
6076 | is inconsistent. On lightly loaded systems this may not matter. | |
6077 | ||
6078 | ||
6079 | Q5019: I need an option that is the opposite of \-bpa-\, that is, a listing of | |
6080 | those addresses generated from a top-level address that have not yet | |
6081 | been delivered. | |
6082 | ||
6083 | A5019: Exim does not keep this information. It saves only the top-level | |
6084 | addresses and the list of addresses that are finished with. At each | |
6085 | delivery attempt, generated addresses are recomputed from scratch. This | |
6086 | makes it possible to correct errors in redirection data that is | |
6087 | causing delivery delays. However, there is an option you can set on a | |
6088 | \redirect\ router that changes things. It is called \one_time\, and if | |
6089 | it is set, the list of generated addresses gets added to the top-level | |
6090 | list at the first delivery attempt, and is never regenerated. Because | |
6091 | top-level address lists must be real email addresses, this option cannot | |
6092 | be used if any of the generated addresses are pipes, files, or | |
6093 | autoreplies. | |
6094 | ||
6095 | ||
6096 | Q5020: How can I make Exim receive incoming mail, queue it, but not attempt to | |
6097 | deliver it? I want to be in this state while moving some mailboxes. | |
6098 | ||
6099 | A5020: Set \queue_only\ in the Exim configuration. Then kill your daemon, | |
6100 | and restart it without the \-q-\ option (i.e. with just the \-bd-\ option), | |
6101 | so that it does not spawn any queue runners. This stops all deliveries, | |
6102 | remote as well as local. | |
6103 | ||
6104 | ||
6105 | Q5021: What does Exim use for POP and IMAP as a default? Do I have to install | |
6106 | anything else? | |
6107 | ||
6108 | A5021: Yes. Exim provides MTA functionality. That is, it delivers mail. POP and | |
6109 | IMAP are two of several ways of reading previously-delivered mail. Exim | |
6110 | does not provide that functionality. You need to install POP and/or IMAP | |
6111 | daemons; there are several to choose from. There is a mailing list at | |
6112 | //pop-imap@exim.org// for the discussion of POP/IMAP issues. | |
6113 | ||
6114 | ||
6115 | Q5022: Is there an easy way of removing all queued messages at once in a safe | |
6116 | way? | |
6117 | ||
6118 | A5022: Try this command: | |
6119 | ||
6120 | ==> exim -bp | awk '/^ *[0-9]+[mhd]/{print "exim -Mrm " $3}' | sh | |
6121 | ||
6122 | ||
6123 | Q5023: Why does Exim do \*ident*\ callbacks by default? Isn't this just a waste | |
6124 | of resources? I've been told this is an ancient way of authentication. | |
6125 | Is it obsolete? | |
6126 | ||
6127 | A5023: This is a common misunderstanding, at least partially resulting from the | |
6128 | incorrect naming of the protocol when it was first published. | |
6129 | The service on port 113 is an identification service, which allows a | |
6130 | target host to record information identifying the user responsible for | |
6131 | making a connection to it. The information may not be intelligible to | |
6132 | the recording host - it could, for example, be encrypted so that only | |
6133 | someone on the calling host can make sense of it. It is useful for | |
6134 | providing additional information in an audit trail. | |
6135 | ||
6136 | At least one site has found \^ident^\ effective against two rather | |
6137 | prevalent kinds of open proxy (whether already blacklisted at the RBLs | |
6138 | or not). An ACL statement is used to reject mail from servers that | |
6139 | return \^ident^\ strings of \"squid"\ and \"CacheFlow Server"\. | |
6140 | Snippets such as this in the RCPT ACL do the trick: | |
6141 | ||
6142 | ==> deny condition = ${if eq{$sender_ident}{CacheFlow Server}{1}{0}} | |
6143 | message = Rejected - appears to be an unsecured proxy: $sender_ident | |
6144 | ||
6145 | The likelihood that a genuine mail process would return those specific | |
6146 | ident strings is vanishingly small. | |
6147 | ||
6148 | The \^ident^\ data should not be used for authentication in any form | |
6149 | except on a closed secure network between cooperating hosts (probably | |
6150 | not even then). The information from the source host is only as reliable | |
6151 | as the host itself. If it's not under your control then you have to | |
6152 | treat the information as opaque data that can be used only by the | |
6153 | sysadmin of the source system to trace back connection data. Some | |
6154 | \^ident^\ implementations send out opaque cookies or DES encrypted | |
6155 | information. \^Ident^\ is hugely useful at times - especially for | |
6156 | checking back on connections from multiuser machines (as opposed to | |
6157 | one-person desktop boxes). | |
6158 | ||
6159 | You can stop Exim making ident calls by adding | |
6160 | ||
6161 | ==> rfc1413_query_timeout = 0s | |
6162 | ||
6163 | to its configuration, but it is better to leave it active (reducing the | |
6164 | timeout to 10s or less if it is causing problems) - it costs very | |
6165 | little, and in cases of mail forgery from a multiuser system can track | |
6166 | the sinner concerned very quickly. | |
6167 | ||
6168 | ||
6169 | Q5024: I often have the problem that a message gets stuck in the mail queue and | |
6170 | I want it to be bounced to a certain address. | |
6171 | ||
6172 | A5024: You can do this using a combination of four command line options, like | |
6173 | this: | |
6174 | ||
6175 | ==> exim -Mf 14Fdlq-0003kM-00 | |
6176 | exim -Mmad 14Fdlq-0003kM-00 | |
6177 | exim -Mar 14Fdlq-0003kM-00 new@ddress | |
6178 | exim -M 14Fdlq-0003kM-00 | |
6179 | ||
6180 | The first command freezes the message so that a queue runner won't start | |
6181 | to deliver it while you are changing things. The second command marks | |
6182 | all existing recipients as delivered. The third command adds a new | |
6183 | recipient, and the fourth command forces a delivery of the message, | |
6184 | which will cause it to be delivered to the new address, and then | |
6185 | deleted. | |
6186 | ||
6187 | ||
6188 | Q5025: What precautions should I take when editing Exim's run time | |
6189 | configuration file? | |
6190 | ||
6191 | A5025: Edit the file and save the result in a new file. Test the syntax of | |
6192 | the new file by running a command like this: | |
6193 | ||
6194 | ==> exim -bV -C exim.conf.new | |
6195 | ||
6196 | That will check for syntax errors without disturbing your running | |
6197 | configuration. If you are paranoid enough, run, as \/root/\, | |
6198 | ||
6199 | ==> exim -C exim.conf.new <some address> | |
6200 | <some message> | |
6201 | . | |
6202 | ||
6203 | and see if it delivers it. Carry on testing until happy. When happy, | |
6204 | ||
6205 | ==> mv exim.conf.new exim.conf | |
6206 | kill -HUP `cat /var/spool/exim/exim-daemon.pid` | |
6207 | ||
6208 | Then check the Exim log to be sure the daemon restarted OK. Watch the | |
6209 | log for a bit to see that mail is flowing. | |
6210 | ||
6211 | ||
6212 | Q5026: Is exim able to use RFC 2645, \*On-demand Mail Relay*\ (ODMR)? | |
6213 | ||
6214 | A5026: No. | |
6215 | ||
6216 | ||
6217 | Q5027: Is there any way I can send bounces to the postmaster, and nobody else? | |
6218 | Basically, I want to receive them, and I don't want the reply/from | |
6219 | person to get them. If I think they need it I will forward it myself. | |
6220 | ||
6221 | A5027: Put \"errors_to=postmaster"\ on every router. | |
6222 | ||
6223 | ||
6224 | Q5028: When I HUP the Exim daemon, the name shown in the process table changes | |
6225 | from \(/usr/lib/sendmail)\ (which is a symlink) to the real binary name. | |
6226 | Can I change this? | |
6227 | ||
6228 | A5028: Add this to your Exim configuration: | |
6229 | ||
6230 | ==> exim_path = /usr/lib/sendmail | |
6231 | ||
6232 | ||
6233 | Q5029: A message with a recipient address that contains a non-printing character | |
6234 | is stuck on my mail queue. How can I remove this address? | |
6235 | ||
6236 | A5029: You can use the \-Mmd-\ command line option to mark a recipient address | |
6237 | ``delivered'', which effectively removes it. If you are using the Bash | |
6238 | shell, you can enter non-printing characters using an escape sequence. | |
6239 | For example: | |
6240 | ||
6241 | ==> exim -Mmd 15HKvU-00013Q-00 $'\240'abc@x.y.z | |
6242 | ||
6243 | In this example, the first character of the local part has a code value | |
6244 | of 240. If you are using a shell that does not support this, create the | |
6245 | command in a file and run it as a shell script. | |
6246 | ||
6247 | ||
6248 | Q5030: I am using exim in a two queues scenario, with two different | |
6249 | configuration files. How can I run a second copy of \^eximon^\ to | |
6250 | inspect and modify the alternate queue? | |
6251 | ||
6252 | A5030: Use these commands (or put them in a script): | |
6253 | ||
6254 | ==> EXIMON_EXIM_CONFIG=/your/path/exim/configure.alternate | |
6255 | export EXIMON_EXIM_CONFIG | |
6256 | /your/path/exim/bin/eximon | |
6257 | ||
6258 | ||
6259 | Q5031: Why is there no sender address on bounce messages? It shows up as "<>". | |
6260 | ||
6261 | A5031: See the answer to Q0042. | |
6262 | ||
6263 | ||
6264 | Q5032: Are there any Exim web-based administration scripts? | |
6265 | ||
6266 | A5032: No (as far as is known). It seems likely that producing one that is | |
6267 | generic enough would be a difficult task. | |
6268 | ||
6269 | ||
6270 | Q5033: How can I send a copy of all outgoing messages to another mailbox? | |
6271 | ||
6272 | A5033: The most straightforward way is to set up a system filter, and include | |
6273 | a command such as: | |
6274 | ||
6275 | ==> unseen deliver mailbox@whatever.domain | |
6276 | ||
6277 | This sends a copy of every message to //mailbox@whatever.domain// | |
6278 | (unless the message already has that recipient - Exim never does | |
6279 | duplicate deliveries). | |
6280 | ||
6281 | To save only ``outgoing'' messages, you need to come up with a | |
6282 | definition of what ``outgoing'' means. Typically, this might be a check | |
6283 | on the sender address and/or on the originating host. Here is an | |
6284 | example: | |
6285 | ||
6286 | ==> if $sender_address_domain is mydomain.com and | |
6287 | ${mask:$sender_host_address/24} is 192.168.324.0/24 | |
6288 | then | |
6289 | unseen deliver mailbox@whatever.domain | |
6290 | endif | |
6291 | ||
6292 | ||
6293 | Q5034: Is there any way to make the \queue_only\ option conditional? I would | |
6294 | like the ability to queue messages from external sources while deliver | |
6295 | locally generated email as normal. | |
6296 | ||
6297 | A5034: There is no direct way of doing this. However, you can achieve the | |
6298 | effect. In one of your ACLs that checks incoming mail from external | |
6299 | sources, put | |
6300 | ||
6301 | ==> warn control = queue_only | |
6302 | ||
6303 | You can add other conditions as well, of course. | |
6304 | ||
6305 | ||
6306 | ||
6307 | 91. MAC OS X | |
6308 | ||
6309 | Q9101: How can I install Exim on Mac OS X? | |
6310 | ||
6311 | A9101: (1) There is useful advice on this web page: | |
6312 | \?http://www.afp548.com/Articles/Jaguar/exim410.html?\. | |
6313 | ||
6314 | (2) There is a package installer available at this URL: | |
6315 | \?ftp://members.aol.com/AFP548dotcom/EximInstaller.sit?\. | |
6316 | ||
6317 | (3) There is another package installer for the combination of MySQL, | |
6318 | Exim, Exiscan, CourierIMAP, and SpamAssassin at this URL: | |
6319 | \?http://maxo.captainnet.net/installs/mail-install.html?\. | |
6320 | ||
6321 | ||
6322 | ||
6323 | 92. FREEBSD | |
6324 | ||
6325 | Q9201: On FreeBSD, \(/usr/sbin/sendmail)\ is a symbolic link to | |
6326 | \(/usr/sbin/mailwrapper)\; it doesn't contain the Sendmail binary. How | |
6327 | should I replace Sendmail with Exim on FreeBSD? | |
6328 | ||
6329 | A9201: There is a file called \(/etc/mail/mailer.conf)\ which selects what to | |
6330 | run for various MTA calls. Instead of changing \(/usr/sbin/sendmail)\, | |
6331 | you should edit this file instead, to read something like this: | |
6332 | ||
6333 | ==> sendmail /usr/exim/bin/exim | |
6334 | send-mail /usr/exim/bin/exim | |
6335 | mailq /usr/exim/bin/exim -bp | |
6336 | newaliases /usr/bin/true | |
6337 | ||
6338 | You probably also need to edit \(/etc/periodic.conf)\; see Q9202. | |
6339 | ||
6340 | ||
6341 | Q9202: A script that FreeBSD runs nightly uses \^mailq^\ with the \-Ac-\ | |
6342 | parameter. Why doesn't Exim recognize this? | |
6343 | ||
6344 | A9202: \-Ac-\ is a Sendmail option that requests that mailq ``Show the mail | |
6345 | submission queue specified in \(/etc/mail/submit.cf)\ instead of the | |
6346 | MTA queue specified in \(/etc/mail/sendmail.cf)\''. Exim doesn't have | |
6347 | the concept of a ``submission queue''. You can disable this feature | |
6348 | of the nightly script by adding the line | |
6349 | ||
6350 | ==> daily_status_include_submit_mailq="NO" # No separate 'submit' queue | |
6351 | ||
6352 | to the file \(/etc/periodic.conf)\. | |
6353 | ||
6354 | ||
6355 | Q9203: How can I use Exim for authenticated SMTP using Cyrus on FreeBSD? | |
6356 | ||
6357 | A9203: This web page may help: \?http://www.munk.nu/exim/exim-freebsd-asmtp.php?\. | |
6358 | ||
6359 | ||
6360 | ||
6361 | 93. HP-UX | |
6362 | ||
6363 | Q9301: I'm trying to compile on an HP machine and I don't have \^gcc^\ there. So I | |
6364 | put \"CC=cc"\ in the \(Local/Makefile)\, but I got this error: | |
6365 | ||
6366 | ==> (Bundled) cc: "buildconfig.c", line 54: error 1705: Function prototypes | |
6367 | are an ANSI feature. | |
6368 | ||
6369 | A9301: The bundled compiler is not an ANSI C compiler. You either have to get a | |
6370 | copy of \^gcc^\ from the HPUX Software Porting Archives or buy the ANSI cc | |
6371 | from HP. The advice given by one user of HP systems on the Exim | |
6372 | mailing list was as follows: | |
6373 | ||
6374 | \*Personally, I wouldn't use anything but the ANSI C compiler. gcc | |
6375 | works for compilation, but it doesn't know squat about PA-RISC chips | |
6376 | past the 1.0 rev. Since then, HP has come out with PA-RISC 1.1, 2.0, | |
6377 | and 2.1, each with better features. gcc will compile for them, but it | |
6378 | doesn't produce anywhere near the optimization that HP's compiler | |
6379 | does.*\ | |
6380 | ||
6381 | \*I took the gcc road when we moved from FreeBSD to HP-UX because I was | |
6382 | familiar with it. After 6 months, I had to go and re-port everything | |
6383 | over when we realized that gcc wasn't going to do it for us long-term. | |
6384 | If I could give advice to any new HP-UX admin: don't use gcc if you | |
6385 | can afford the ANSI C compiler. Based on the cost of even the lowest | |
6386 | HP workstation, that usually isn't a problem.*\ | |
6387 | ||
6388 | ||
6389 | ||
6390 | 94. BSDI | |
6391 | ||
6392 | Q9401: On BSDI 4.0, Exim built with Perl support exits with the error message | |
6393 | ||
6394 | ==> ./exim: can't load library 'libperl.so' | |
6395 | ||
6396 | A9401: You probably compiled perl5 yourself, without looking into | |
6397 | ||
6398 | ==> /usr/src/contrib/perl5/perl5.004_02/hints/bsdos.sh | |
6399 | ||
6400 | first. The problem is that the command | |
6401 | ||
6402 | ==> perl5 -MExtUtils::Embed -e ldopts | |
6403 | ||
6404 | doesn't give you sufficient flags to link something with libperl. | |
6405 | Since 5.004_02 the \(hints/bsdos.sh)\ file has changed to adapt to the | |
6406 | changes between BSDI 3.1 and 4.0, but it is still not entirely right. | |
6407 | ||
6408 | The solution is, when you compile perl, change the \ccdlflags\ | |
6409 | variable in config.sh to: | |
6410 | ||
6411 | ==> -rdynamic -Wl,-rpath,/usr/local/lib/perl5/5.00502/i386-bsdos/CORE | |
6412 | ||
6413 | (or something similar). Alternatively, you can run \(./Configure)\ and | |
6414 | answering the question \*Any special flags to pass to cc to use dynamic | |
6415 | loading?*\ with the above line. It is not known what \-rdynamic-\ means | |
6416 | (it's not apparently documented in any man page), but that's what BSDI | |
6417 | guys did to compile perl5 which comes with BSDI 4.0 distribution. | |
6418 | ||
6419 | ||
6420 | ||
6421 | 95. IRIX | |
6422 | ||
6423 | Q9501: The IP addresses for incoming calls are all being given as | |
6424 | 255.255.255.255 or 0.0.0.0. | |
6425 | ||
6426 | A9501: This problem should no longer occur because a workaround has been | |
6427 | installed in Exim. | |
6428 | ||
6429 | ||
6430 | ||
6431 | 96. LINUX | |
6432 | ||
6433 | Q9601: Exim is mysteriously crashing, usually when forking to send a delivery | |
6434 | error message. | |
6435 | ||
6436 | A9601: This has been seen in cases where Exim has been incorrectly built with | |
6437 | a muddled combination of an \(ndbm.h)\ include file and a non-matching | |
6438 | DBM library. | |
6439 | ||
6440 | Faults like this have also been seen on systems with faulty motherboards. | |
6441 | You could try to compile the Linux kernel 10 times - if the compile | |
6442 | process stops with signal 11, your hardware is to blame. | |
6443 | ||
6444 | ||
6445 | Q9602: I want to use \^logrotate^\ which is standard with RH5.2 Linux to rotate | |
6446 | my mail logs. Anyone worked out the \^logrotate^\ config file that will | |
6447 | do this? | |
6448 | ||
6449 | A9602: Here's one suggestion: | |
6450 | ||
6451 | ==> /var/log/exim/main.log { | |
6452 | create 644 exim exim | |
6453 | rotate 4 | |
6454 | compress | |
6455 | delaycompress | |
6456 | } | |
6457 | ||
6458 | The sleep is added to allow things to close the log file prior to | |
6459 | compression. You also need similar entries for the panic log and the | |
6460 | reject log, of course. | |
6461 | ||
6462 | ||
6463 | Q9603: I'm seeing the message \*inetd[334]: imap/tcp server failing (looping), | |
6464 | service terminated*\ on a RedHat 5.2 system, causing \^imap^\ connections to | |
6465 | be refused. The \^imapd^\ in use is Washington Univers 12.250. Could this | |
6466 | be anything to do with Exim? | |
6467 | ||
6468 | A9603: No, it's nothing to do with Exim, but here's the answer anyway: there | |
6469 | is a maximum connection rate for \^inetd^\. If connections come in faster | |
6470 | than that, it thinks a caller is looping. The default setting on RedHat | |
6471 | 5.2 is 40 calls in any one minute before \^inetd^\ thinks there's a problem | |
6472 | and suspends further calls for 10 mins. This default setting is very | |
6473 | conservative. You should probably increase it by a factor of 10 or 20. | |
6474 | For example: | |
6475 | ||
6476 | ==> imap stream tcp nowait.400 root /usr/sbin/tcpd /usr/local/etc/imapd | |
6477 | ||
6478 | The rate setting is the number following ``nowait''. This syntax seems to | |
6479 | be specific to the Linux version of \^inetd^\. Other operating systems | |
6480 | provide similar functionality, but in different ways. | |
6481 | ||
6482 | ||
6483 | Q9604: I get the \*too many open files*\ error especially when a lot of messages | |
6484 | land for Majordomo at the same time. | |
6485 | ||
6486 | A9604: The problem appears to be the number of open files the system can | |
6487 | handle. This is changable by using the proc filesystem. To your | |
6488 | \(/etc/rc.d/rc.local)\ file append something like the following: | |
6489 | ||
6490 | ==> # Now System is up, Modify kernel parameters for max open etc. | |
6491 | ||
6492 | ==> if [ -f /proc/sys/kernel/file-max ]; then | |
6493 | echo 16384 >> /proc/sys/kernel/file-max | |
6494 | fi | |
6495 | if [ -f /proc/sys/kernel/inode-max ]; then | |
6496 | echo 24576 >> /proc/sys/kernel/inode-max | |
6497 | fi | |
6498 | if [ -f /proc/sys/kernel/file-nr ]; then | |
6499 | echo 2160 >> /proc/sys/kernel/file-nr | |
6500 | fi | |
6501 | ||
6502 | By echoing the value you want for file-max to the file \(file-max)\ etc., | |
6503 | you actually change the kernel parameters. | |
6504 | ||
6505 | ||
6506 | Q9605: I installed debian 2.2 linux on a small 325mb 486 laptop. When I try | |
6507 | to test the Mail program, I get the following error: \*Failed to open | |
6508 | configuration file /etc/exim.conf*\. | |
6509 | ||
6510 | A9605: The Debian installation should have given you \(/usr/sbin/eximconfig)\, | |
6511 | which asks you some questions and then sets up the configuration file | |
6512 | in \(/etc/exim.conf)\. Try running that (you'll probably need \/root/\) and see | |
6513 | how it goes. In any case you get a thoroughly commented conf file at | |
6514 | the end, which will give you a sample from which to work if you need | |
6515 | further modification. | |
6516 | ||
6517 | The Exim docs in the Debian package are in \(/usr/doc/exim)\ where the full | |
6518 | reference manual is \(spec.txt.gz)\. | |
6519 | ||
6520 | ||
6521 | Q9606: I'm having trouble configuring Exim 4 on a Debian system. How does | |
6522 | \(/etc/exim4/conf.d)\ work? | |
6523 | ||
6524 | A9606: The Debian Exim 4 package uses a quite uncommon, but elegant, | |
6525 | method of configuration where the ``real'' Exim configuration file is | |
6526 | assembled from a tree of snippets by a script invoked just before the | |
6527 | daemon is started (see Q9608). | |
6528 | ||
6529 | This fits very well into the Debian system of configuration file | |
6530 | management and is a great ease for the automatic configuration with | |
6531 | Debconf. However, it is \*very*\ different from the normal way Exim 4 is | |
6532 | configured. Non-Debian users on the Exim mailing list will probably have | |
6533 | difficulty in trying to answer specific questions about it. You may have | |
6534 | to find a Debian expert. | |
6535 | ||
6536 | ||
6537 | Q9607: I'm having difficulties trying to make Exim 4 with Redhat 9 and Berkeley | |
6538 | DB 4. | |
6539 | ||
6540 | A9607: Have you remembered to install the db4-devel package? | |
6541 | ||
6542 | ||
6543 | Q9608: I'm running Exim 3 under Debian, and want to upgrade to Exim 4. How | |
6544 | difficult is it? | |
6545 | ||
6546 | A9608: A user who did this, using the Debian Exim 4 package, reported as | |
6547 | follows: | |
6548 | ||
6549 | (1) The exim4 package installs easily, and the exim (3.38) package | |
6550 | uninstalls at the same time. | |
6551 | ||
6552 | (2) Exim runs from \^inetd^\. Exim4 runs from \^/etc/init.d^\. \*Much*\ nicer! | |
6553 | ||
6554 | (3) The exim conffile lives in \(/etc/exim/exim.conf)\. The exim4 conffile | |
6555 | lives in \(/var/lib/exim4/config.autogenerated)\. It is, as the name | |
6556 | suggests, autogenerated. | |
6557 | ||
6558 | (4) A new directory is created called \(/etc/exim4)\. This contains the | |
6559 | conffiles to generate the above config. You make changes here. | |
6560 | ||
6561 | (5) Once you have made changes to the files in \(/etc/exim4)\ you run the | |
6562 | script \^update-exim4.conf^\ which generates a replacement | |
6563 | \(config.autogenerated)\. | |
6564 | ||
6565 | [Added comment by the Debian maintainer, slightly edited: | |
6566 | You also need to tell the Exim daemon to reread the changed | |
6567 | configuration. You can do this using SIGHUP by hand. Alternatively, | |
6568 | instead of running \^update-exim4.conf^\ you can use | |
6569 | ||
6570 | ==> invoke-rc.d exim4 reload | |
6571 | ||
6572 | which does the rebuild and also tells Exim to reread the changed | |
6573 | configuration.] | |
6574 | ||
6575 | (6) In my experience, you need to \*carefully*\ check the generated | |
6576 | configs. eg, it did not generate a system filter file reference in the | |
6577 | \(config.autogenerated)\. I didn't bother too much, since this is a home | |
6578 | setup. | |
6579 | ||
6580 | (7) All of this may be in the docs. I've read some of them, obviously, | |
6581 | but didn't come across an actual upgrade guide. | |
6582 | ||
6583 | [The Debian maintainer says: | |
6584 | \(/usr/share/doc/exim4-base/README.Debian.gz)\ and \^update-exim4.conf(8)^\ | |
6585 | should answer most of the questions.] | |
6586 | ||
6587 | (8) I've still got some minor things to tweak to get back to where I | |
6588 | was before with Exim 3. But overall, it's no drama. | |
6589 | ||
6590 | ||
6591 | Q9609: Why do some servers refuse SMTP connections from my Linux box, but accept | |
6592 | connections from hosts running other operating systems? | |
6593 | ||
6594 | A9609: If you are sure this isn't a policy issue (that is, your box isn't | |
6595 | administratively blocked for some reason), this may be because your | |
6596 | Linux box has ECN (Explicit Congestion Notification) enabled in its | |
6597 | TCP/IP stack. There are many broken firewalls that refuse connections | |
6598 | from ECN-enabled hosts. You can check the state of your box by running | |
6599 | ||
6600 | ==> cat /proc/sys/net/ipv4/tcp_ecn | |
6601 | ||
6602 | If the value is "1", you have ECN enabled. You can turn it off by | |
6603 | running this command: | |
6604 | ||
6605 | ==> echo "0" > /proc/sys/net/ipv4/tcp_ecn | |
6606 | ||
6607 | ||
6608 | ||
6609 | 97. SUN SYSTEMS | |
6610 | ||
6611 | Q9701: Exim builds fine with \^gcc^\ on SunOS 4 but crashes inside \^^sscanf()^^\. | |
6612 | ||
6613 | A9701: Make sure you are liking with the GNU \^ld^\ linker and not the system | |
6614 | version of \^ld^\. | |
6615 | ||
6616 | ||
6617 | Q9702: How can I get rid of spurious \"^M"\ characters in messages sent from | |
6618 | CDE \^dtmail^\? | |
6619 | ||
6620 | A9702: CDE \^dtmail^\ passes messages to Exim via the command line interface with | |
6621 | lines terminated by CRLF, instead of the Unix convention of just LF. As | |
6622 | Exim is an 8-bit clean program it treats the CR as just another data | |
6623 | character. Exim has a command line option called \-dropcr-\ which causes | |
6624 | it to ignore all CR characters in an incoming non-SMTP message. You | |
6625 | should configure \^dtmail^\ to add this option to the command it uses to | |
6626 | call Exim (using the path \(/usr/lib/sendmail)\). However, it has been | |
6627 | reported that it isn't possible to change this call from \^dtmail^\ by any | |
6628 | official means. An alternative approach is to replace \(/usr/lib/sendmail)\ | |
6629 | by a filtering script which removes the spurious CRs from the input | |
6630 | before passing it to Exim. | |
6631 | ||
6632 | ||
6633 | Q9703: On SunOS 4 Exim crashes when looking up domains in the DNS that have | |
6634 | more than 10 A records. | |
6635 | ||
6636 | A9703: There are Sun library patches to fix this. It is not Exim's problem. | |
6637 | For 4.13_U1 the patch is 101558-xx; for 4.1.3 the patch is 100891-xx. | |
6638 | From the README: \*1054748 ftp, ping dump core when connecting to a host | |
6639 | with multiple DNS A records.*\ An alternative is to build another | |
6640 | resolver library - such as the ones that are part of the \^bind^\ | |
6641 | distribution - and explicitly link against those. | |
6642 | ||
6643 | ||
6644 | Q9704: I am experiencing mailbox locking problems with Sun's \^mailtool^\ used | |
6645 | over a network. | |
6646 | ||
6647 | A9704: Under the \"Expert"\ settings of \^mailtool^\ is a option to turn on \*Use | |
6648 | network aware mail file locking*\. By default \^dtmail^\ has this set, but | |
6649 | \^mailtool^\ doesn't. You should set it. The help info on \^dtmail^\ has this | |
6650 | to say about it: | |
6651 | ||
6652 | \*Mailer tries to prevent two different instances of itself from opening | |
6653 | the same mail file at the same time through a technique that detects | |
6654 | this access when both instances of Mailer and the file are all on the | |
6655 | same machine. A network-aware mail file locking protocol is available | |
6656 | that uses ToolTalk to coordinate instances of Mailer running from more | |
6657 | than one machine, or mail files accessed over the network. Mailer can | |
6658 | only change this option when first opening a mail file.*\ | |
6659 | ||
6660 | If you are using the SunOS4 version of \^mailtool^\, this apparently | |
6661 | doesn't work. The only thing which does seem to work it getting the user | |
6662 | to hit the \"done"\ button to make it release the lock. | |
6663 | ||
6664 | ||
6665 | Q9705: Exim has been crashing on my Solaris x86 system, apparently while | |
6666 | running DBM functions. | |
6667 | ||
6668 | A9705: The use of \^ndbm^\ with \^gcc^\ has caused problems on x86 Solaris systems. | |
6669 | Try changing one or the other; using either DB with gcc, or Sun's | |
6670 | WS compiler with \^ndbm^\, has fixed this in the past. | |
6671 | ||
6672 | ||
6673 | Q9706: The \^exiwhat^\ utility isn't working for me on a Solaris 2 system. | |
6674 | ||
6675 | A9706: Have you got \(/usr/ucb)\ on your path? If so, it is probably picking up the | |
6676 | wrong version of the \^ps^\ command. The \^exiwhat^\ script is built on | |
6677 | Solaris to expect the normal Solaris version of \^ps^\. | |
6678 | ||
6679 | ||
6680 | Q9707: How do I stop Sun's \^dtcm^\ from hanging? | |
6681 | ||
6682 | A9707: From qmail's FAQ: \*There is a novice programming error in dtcm, known as | |
6683 | ``failure to close the output side of the pipe in the child.'' Sun has, | |
6684 | at the time of this writing, not yet provided a patch.*\ | |
6685 | ||
6686 | ||
6687 | Q9708: I want Exim to use only the resolver (i.e. ignore \(/etc/hosts)\), but don't | |
6688 | want to alter the \(nsswitch.conf)\ file in Solaris 2. | |
6689 | ||
6690 | A9708: You need to rebuild Exim after fiddling with \(OS/os.h-SunOS5)\: | |
6691 | ||
6692 | ==> #define gethostbyaddr res_gethostbyaddr | |
6693 | #define gethostbyname res_gethostbyname | |
6694 | #define endhostent res_endhostent | |
6695 | #define endnetent res_endnetent | |
6696 | #define gethostent res_gethostent | |
6697 | #define getnetbyaddr res_getnetbyaddr | |
6698 | #define getnetbyname res_getnetbyname | |
6699 | #define getnetent res_getnetent | |
6700 | #define sethostent res_sethostent | |
6701 | #define setnetent res_setnetent | |
6702 | ||
6703 | Note that \-lnsl-\ is still needed in the Makefile as it | |
6704 | contains code used by the NIS lookup and also the \^^inet_addr()^^\ function | |
6705 | that Exim uses. | |
6706 | ||
6707 | ||
6708 | Q9709: When I try to compile Exim 4.x on Solaris 2.5.1 I get an error along the | |
6709 | lines of \*no such field in struct as 'value.ui32'*\. | |
6710 | ||
6711 | A9709: Look in the Exim file \(OS/os.h-SunOS5.h)\ for the line | |
6712 | ||
6713 | ==> #define LOAD_AVG_FIELD value.ui32 | |
6714 | ||
6715 | and change \"ui32"\ to \"ul"\ (that's u followed by the letter ell, not | |
6716 | the digit one). Solaris 2.5.1 is getting \*very*\ old now... | |
6717 | ||
6718 | ||
6719 | ||
6720 | 98. CONFIGURATION COOKBOOK | |
6721 | ||
6722 | Q9801: How do I configure Exim as part of TPC (\?http://www.tpc.int?\)? | |
6723 | ||
6724 | A9801: Suppose you want to accept faxes destined for 1(801)539-*. These are | |
6725 | addressed to the domain //9.3.5.1.0.8.1.tpc.int//. Set up a transport to | |
6726 | handle the delivery: | |
6727 | ||
6728 | ==> tpc: | |
6729 | driver = pipe | |
6730 | command = /usr/local/tpc/tpcmailer.pl $local_part@$domain \ | |
6731 | $sender_address | |
6732 | pipe_as_creator | |
6733 | ||
6734 | \(/usr/local/tpc/tpcmailer.pl)\ is the mail processing script that can | |
6735 | be obtained from the TPC distribution. Create a router to route mail | |
6736 | for the TPC domain to that transport. This must be placed before your | |
6737 | other routers: | |
6738 | ||
6739 | ==> tpc_router: | |
6740 | driver = accept | |
6741 | transport = tpc | |
6742 | domains = *.9.3.5.1.0.8.1.tpc.int | |
6743 | ||
6744 | Of course, there are other things to do as well before your system is | |
6745 | a functioning TPC server. | |
6746 | ||
6747 | ||
6748 | Q9802: How do I configure Exim so that it sends mail to the outside world only | |
6749 | from a restricted list of our local users? | |
6750 | ||
6751 | A9802: You will need to have a convenient way of checking the list. If it is | |
6752 | only a handful of users, you could just list them inline. Otherwise, you | |
6753 | need to put them in a file or database. Let's suppose you've just got a | |
6754 | list in a file. Put this as your first router: | |
6755 | ||
6756 | ==> check_outgoing: | |
6757 | driver = redirect | |
6758 | domains = ! +local_domains | |
6759 | senders = ! : ! lsearch;/etc/permitted/senders | |
6760 | allow_fail | |
6761 | data = :fail: you are not allowed to send outside | |
6762 | ||
6763 | The senders should be listed as complete addresses, with both a local | |
6764 | part and a domain. For a large list, use a DBM or cdb file instead, or | |
6765 | a database. The first item in the \senders\ list is empty, to match the | |
6766 | empty sender. This is necessary because bounce messages have null | |
6767 | senders. | |
6768 | ||
6769 | ||
6770 | Q9803: A site for which I provide secondary MX is down for some time. Is there | |
6771 | a way to run the queue for that destination separately from the main | |
6772 | queue? | |
6773 | ||
6774 | A9803: No, because Exim does not have the concept of ``the queue for that | |
6775 | destination''. It simply has a single pool of messages awaiting delivery | |
6776 | (and some of them may have several destinations). The best approach to | |
6777 | this is to arrange for all messages for the site to be saved somewhere | |
6778 | other than the main spool, either on a separate dedicated MTA, or in | |
6779 | BSMTP files. | |
6780 | ||
6781 | ||
6782 | Q9804: We want to be able to temporarily lock out a user by disabling the | |
6783 | password and moving the home directory to another place. How can we | |
6784 | arrange to reject mail for users in this state? | |
6785 | ||
6786 | A9804: Change the home directory pointer in the passwd file to something | |
6787 | distinctive. For example, we use \(/home/CANCELLED)\ for cancelled users. | |
6788 | Then you can pick up such users with this router, which is placed | |
6789 | immediately after \%system_aliases%\: | |
6790 | ||
6791 | ==> cancelled_users: | |
6792 | driver = redirect | |
6793 | check_local_user | |
6794 | condition = ${if eq {$home}{/home/CANCELLED}{yes}{no}} | |
6795 | allow_fail | |
6796 | data = :fail: this account is cancelled | |
6797 | ||
6798 | ||
6799 | Q9805: How can I configure Exim so that all mails addressed to | |
6800 | //something@username.domain.net// get delivered to | |
6801 | \(/var/spool/mail/username)\? | |
6802 | ||
6803 | A9805: Assuming that you have set up //username// as a normal user, with | |
6804 | conventional routing for //username@domain.net// to that mailbox, all | |
6805 | you need to do is set up a redirection, using a router like this: | |
6806 | ||
6807 | ==> user_in_domain: | |
6808 | driver = redirect | |
6809 | data = ${if match{$domain}{\N^(.*)\.domain\.net$\N}\ | |
6810 | {$1}fail}@domain.net | |
6811 | ||
6812 | If you set \envelope_to\ in the \%appendfile%\ transport, the original | |
6813 | envelope address is preserved in the message in an ::Envelope-to:: | |
6814 | header line. | |
6815 | ||
6816 | ||
6817 | Q9806: How do I get exim not to add a ::Sender:: header to locally originated | |
6818 | mail? | |
6819 | ||
6820 | A9806: It adds it only if the ::From:: header doesn't correspond to the user | |
6821 | sending the message. You can suppress this by setting | |
6822 | \no_local_from_check\. If your real question is \*How do I submit mail | |
6823 | from UUCP without it adding ::Sender::?*\, see Q1503. | |
6824 | ||
6825 | ||
6826 | Q9807: Is there any way to have messages sent to a specific local address | |
6827 | delayed by - say - 24 hours? | |
6828 | ||
6829 | A9807: Set up a router like this: | |
6830 | ||
6831 | ==> delay: | |
6832 | driver = redirect | |
6833 | domains = the.domain | |
6834 | local_parts = thelocalpart | |
6835 | condition = ${if < {$message_age}{86400}{yes}{no}} | |
6836 | allow_defer | |
6837 | data = :defer: message not old enough | |
6838 | no_verify | |
6839 | ||
6840 | Of course, this will also have the effect of setting a retry time for | |
6841 | the address. You may want to set a special retry rule for it. Note the | |
6842 | use of \no_verify\ to ensure that this router is not used when Exim is | |
6843 | verifying addresses. | |
6844 | ||
6845 | ||
6846 | Q9808: I have a mailing list exploder on one host, and three other hosts where | |
6847 | I want to do the actual deliveries from. How can I get Exim to split | |
6848 | a message into groups of recipients between the three hosts? | |
6849 | ||
6850 | A9808: Set up a router that routes all remote addresses to a specific | |
6851 | transport, with a list of your three hosts. For example: | |
6852 | ||
6853 | ==> send_to_three: | |
6854 | driver = manualroute | |
6855 | transport = to_three_smtp | |
6856 | route_list = !+local_domains hostA:hostB:hostC | |
6857 | ||
6858 | The transport looks like this: | |
6859 | ||
6860 | ==> to_three_smtp: | |
6861 | driver = smtp | |
6862 | hosts_randomize | |
6863 | ||
6864 | By setting \hosts_randomize\, you request that the host list be sorted | |
6865 | randomly each time the transport is called, in order to spread the load. | |
6866 | The number of times the transport is called for each message depends on | |
6867 | the setting of the global option \remote_max_parallel\. If it is set to | |
6868 | 1, the transport is called only once for each message, so only one host | |
6869 | is used, but different messages use different hosts because of the | |
6870 | randomizing. | |
6871 | ||
6872 | The \max_rcpt\ option (default 100) controls the number of addresses | |
6873 | sent in each copy of the message - several copies are sent over the | |
6874 | same connection if necessary. | |
6875 | ||
6876 | If you want individual messages to be split between the three hosts, you | |
6877 | must set the global option \remote_max_parallel\ to 3. This allows Exim | |
6878 | to run 3 separate instances of the transport at once. It will pass | |
6879 | one-third of all the addresses to each instance. Because the host list | |
6880 | is randomized, not round-robinned, there is no guarantee that a single | |
6881 | message will use all three hosts, but on average it should. | |
6882 | ||
6883 | ||
6884 | Q9809: Can I configure Exim so that my gateway host sends a copy of each | |
6885 | incoming message to each of two internal hosts? | |
6886 | ||
6887 | A9809: The easiest way to do this is to make use of the \unseen\ router option, | |
6888 | and set up two separate routers. You need to be able to identify | |
6889 | incoming messages somehow. Typically this can be done by testing the | |
6890 | domain of the recipient address, in which case the configuration should | |
6891 | contain something like this: | |
6892 | ||
6893 | ==> r1: | |
6894 | driver = manualroute | |
6895 | domains = ! *.your.domain.example | |
6896 | route_data = * host1.your.domain.example | |
6897 | transport = remote_smtp | |
6898 | unseen | |
6899 | ||
6900 | ==> r2: | |
6901 | driver = manualroute | |
6902 | domains = ! *.your.domain.example | |
6903 | route_data = * host2.your.domain.example | |
6904 | transport = remote_smtp | |
6905 | ||
6906 | The \unseen\ setting on \%r1%\ means that after it has accepted an | |
6907 | address, the address is also passed on to \%r2%\, and so two deliveries | |
6908 | occur. | |
6909 | ||
6910 | ||
6911 | Q9810: How can I implement ``SMTP-after-POP'' with Exim? | |
6912 | ||
6913 | A9810: See Q0706. | |
6914 | ||
6915 | ||
6916 | Q9811: I would like to ``tap off'' a proportion of real mail traffic from my | |
6917 | live mail server to use in tests of a new server. I want to preserve the | |
6918 | envelope contents, but to suppress any error notifications to the | |
6919 | original sender. | |
6920 | ||
6921 | A9811: See C046. | |
6922 | ||
6923 | ||
6924 | Q9812: How can I lookup data from a single file using both single IP addresses | |
6925 | and IP address blocks as keys? I want to set \smtp_accept_max_per_host\ | |
6926 | by this means, and also include a default. | |
6927 | ||
6928 | A9812: You cannot do this in a single lookup, because you need separate lookups | |
6929 | for individual addresses and address blocks. However, these lookups can | |
6930 | be nested in a single expansion string. For example, suppose you are | |
6931 | using an lsearch file with entries like this: | |
6932 | ||
6933 | ==> 192.168.34.35: 4 | |
6934 | 192.168.34.0/24: 2 | |
6935 | *: 1 | |
6936 | ||
6937 | You can use this setting: | |
6938 | ||
6939 | ==> smtp_accept_max_per_host = \ | |
6940 | ${lookup{$sender_host_address}lsearch{/path/to/file}\ | |
6941 | {$value}\ | |
6942 | {\ | |
6943 | ${lookup{${mask:$sender_host_address/24}}lsearch*{/path/to/file}}\ | |
6944 | }} | |
6945 | ||
6946 | Note that the first lookup does \*not*\ have an asterisk on the search | |
6947 | type. If you have blocks of different sizes (/24, /26, etc) you have to | |
6948 | configure it to do a separate lookup for each size, with just the final | |
6949 | one using a default. | |
6950 | ||
6951 | ||
6952 | ||
6953 | 99. LIST OF SAMPLE CONFIGURATIONS | |
6954 | ||
6955 | As well as being hyperlinked from the HTML version of this document, each | |
6956 | sample configuration is also available as a file in the \(config.samples)\ | |
6957 | directory, which can be independently downloaded. | |
6958 | ||
6959 | Samples whose names are of the form Cnnn are Exim configurations; those with | |
6960 | names of the form Fnnn are filter file fragments; those with names of the form | |
6961 | Lnnn are sample \^^local_scan()^^\ functions, and those with names of thf form | |
6962 | Snnn are scripts of various kinds. There are other examples of | |
6963 | \^^local_scan()^^\ functions at a number of web sites (for example, | |
6964 | \?http://marc.merlins.org/linux/exim/sa.html?\). | |
6965 | ||
6966 | There are gaps in the C and F numbers because I have omitted the Exim 3 samples | |
6967 | that have not been converted for Exim 4. | |
6968 | ||
6969 | C002: ``Although exim not intended for use in UUCP environment (it doesn't | |
6970 | know anything about bang!path addresses), I'm successfully using it for | |
6971 | delivering mail to UUCP clients.'' | |
6972 | ||
6973 | C006: ``This is how I have configured a PP-inspired vacationnote, there is | |
6974 | (was?) such a feature in PP. The user makes a file \(tripnote)\ in his/her | |
6975 | home directory, the message is passed to the sender once with a short | |
6976 | leading text.'' | |
6977 | ||
6978 | C022: ``This is the Exim configuration file of a machine which delivers mail to | |
6979 | several local domains where the mail is delivered locally, several hairy | |
6980 | domains, handled as described below, and a half-virtual domain, which is | |
6981 | first processed by its special alias file, then processed as other local | |
6982 | domains (including the processing by the global alias file).'' | |
6983 | ||
6984 | C037: An elegant way of using ETRN, which does immediate delivery if the host | |
6985 | is online, but saves mail in a BSMTP file after some time on the queue. | |
6986 | ETRN then re-injects the mail. | |
6987 | ||
6988 | C042: ``Since the Exim 4 configuration needed to get Mailman to work differs a | |
6989 | little bit from Exim 3 and since I still haven't seen a recipe for | |
6990 | Mailman with Exim 4, I'm providing my configuration (based heavily on | |
6991 | \?http://www.exim.org/howto/mailman.html?\).'' | |
6992 | ||
6993 | C043: ``Attached is an Exim 4 config file which is designed for an Exim server | |
6994 | that is put in front of an Exchange 5.5 system but which verifies the | |
6995 | valid addresses that are stored in Exchange via LDAP lookups against the | |
6996 | Exchange server.'' | |
6997 | ||
6998 | C044: ``I thought I'd submit this as an example of an authenticated mail hub | |
6999 | configuration. Several people have asked for it so I thought it | |
7000 | might be of interest.'' | |
7001 | ||
7002 | C045: ``Here it is, for Exim 4.10 and Cyrus IMAPD 2.1.5 using db3/db4-format | |
7003 | mailbox database. This configuration delivers the messages to Cyrus | |
7004 | IMAPD using LMTP over a TCP/IP socket.'' | |
7005 | ||
7006 | C046: ``Deliver a duplicate of some proportion of all messages to a special | |
7007 | machine specified in the file \(/MAIL_TAP_HOST)\, if it exists.'' | |
7008 | ||
7009 | C047: A sample configuration for calling Spamassassin directly from Exim. | |
7010 | ||
7011 | C049: ``I've been seeing a whole bunch of IPs that send me spam or virus mail | |
7012 | and HELOing as one of my own IPs, or as HELO one.of.my.own.domains (or | |
7013 | maybe HELO \primary_hostname\).'' | |
7014 | ||
7015 | C050: A configuration that uses the DNS to implement virtual domains. | |
7016 | ||
7017 | C051: ``I've been working quite hard to come up with a config that reasonably | |
7018 | matches the qmail-ldap setup, without the warts.'' | |
7019 | ||
7020 | F001: ``I thought that the rest of the list may be interested in reviewing our | |
7021 | filter as a starting point for their own system message filter.'' | |
7022 | ||
7023 | F002: ``... program which refused mail from unknown addresses until they mailed | |
7024 | me promising not to spam me ... since I'd already thought through how | |
7025 | to do it in Exim, and knew it'd be slightly easier than falling out of | |
7026 | bed, I went ahead and did it.'' | |
7027 | ||
7028 | F003: ``Here's four checks installed in our system wide filter that knock out | |
7029 | a lot of otherwise hard to detect rubbish.'' | |
7030 | ||
7031 | F004: ``This is an Exim filter snippet to change locally-generated ::Message-Id:: | |
7032 | and ::Resent-Message-Id:: headers to world-unique values.'' | |
7033 | ||
7034 | L001: A \^^local_scan()^^\ function for Exim that calls \^uvscan^\. | |
7035 | ||
7036 | S001: A Perl script for patching the name of the configuration file in an | |
7037 | Exim binary. | |
7038 | ||
7039 | S002: ``When I moved from smail to exim I built a program that took individual | |
7040 | config pieces, stripped all the comments, and built a config file.'' | |
7041 | ||
7042 | *** End of Exim FAQ *** |