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39THE EXIM FAQ
40------------
41
42This is the FAQ for the Exim Mail Transfer Agent. Many thanks to the many
43people who provided the original information. This file would be amazingly
44cluttered if I tried to list them all. Suggestions for corrections,
45improvements, and additions are always welcome.
46
47This version of the FAQ applies to Exim 4.00 and later releases. It has been
48extensively revised, and material that was relevant only to earlier releases
49has been removed. As this caused some whole sections to disappear, I've taken
50the opportunity to re-arrange the sections and renumber everything except the
51configuration samples.
52
53References of the form Cnnn, Fnnn, Lnnn, and Snnn are to the sample
54configuration, filter, \^^local_scan()^^\, and ``useful script'' files. These
55are hyperlinked from the HTML version of this FAQ. They can also be found in
56the separately distributed directory called \(config.samples)\. The primary
57location 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
62There are brief descriptions of these files at the end of this document.
63
64Philip Hazel
2683a02a 65Last update: 12-October-2004
495ae4b0
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66
67
68The 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
1020. GENERAL DEBUGGING
103
104Q0001: Exim is crashing. What is wrong?
105
106A0001: 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
116Q0002: Exim is not working. What is wrong? How can I check what it is doing?
117
118A0002: 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
154Q0003: What does the error \*Child process of address_pipe transport returned
155 69 from command xxx*\ mean?
156
157A0003: 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
168Q0004: My virtual domain setup isn't working. How can I debug it?
169
170A0004: 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
182Q0005: Why is Exim not rejecting incoming messages addressed to non-existent
183 users at SMTP time?
184
185A0005: 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
192Q0006: I've put an entry for \"*.my.domain"\ in a DBM lookup file, but it isn't
193 getting recognized.
194
195A0006: You need to request ``partial matching'' by setting the search type to
196 \partial-dbm\ in order for this to work.
197
198
199Q0007: 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
204A0007: 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
212Q0008: 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
215A0008: 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
228Q0009: What does \*no immediate delivery: too many messages received in one SMTP
229 connection*\ mean?
230
231A0009: 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
244Q0010: Exim puts \*for \[address]\*\ in the ::Received:: headers of some, but not all,
245 messages. Is this a bug?
246
247A0010: 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
255Q0011: 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
258A0011: 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
264Q0012: Exim is unable to route to any remote domains. It doesn't seen to be
265 able to access the DNS.
266
267A0012: 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
274Q0013: What does the error message \*transport system_aliases: cannot find
275 transport driver "redirect" in line 92*\ mean?
276
277A0013: \%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
281Q0014: 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
285A0014: 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
302Q0015: What does the message \*Socket bind() to port 25 for address (any)
303 failed: address already in use*\ mean?
304
305A0015: 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
310Q0016: 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
314A0016: 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
331Q0017: 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
335A0017: \*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
406Q0018: 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
411A0018: 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
444Q0019: There seems to be a problem in the string expansion code: it doesn't
445 recognize references to headers such as \"${h_to}"\.
446
447A0019: The only valid syntax for header references is (for example) \"$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
453Q0020: 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
457A0020: 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
484Q0021: 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
488A0021: 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
496Q0022: What does \*No transport set by system filter*\ in a log line mean?
497
498A0022: 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
505Q0023: 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
511A0023: 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
530Q0024: When I run \"exim -bd -q10m"\ I get \*PANIC LOG: exec of exim -q failed*\.
531
532A0024: 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
538Q0025: 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
545A0025: 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
565Q0026: 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
569A0026: 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
578Q0027: What does the error \*Spool file is locked*\ mean?
579
580A0027: 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
592Q0028: 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
595A0028: You are using a version of Exim built with gcc on an IRIX box.
596 See Q9502.
597
598
599Q0029: I can't seem to figure out why PAM support doesn't work correctly.
600
601A0029: 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
616Q0030: 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
619A0030: 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
624Q0031: Exim is rejecting connections from hosts that have more than one IP
625 address, for no apparent reason.
626
627A0031: 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
632Q0032: 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
638A0032: 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
645Q0033: What does the error \*lookup of host "xx.xx.xx" failed in yyy router*\
646 mean?
647
648A0033: 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
662Q0034: 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
665A0034: 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
672Q0035: 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
675A0035: 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
688Q0036: Why do I get the error \*Permission denied: creating lock file hitching
689 post*\ when Exim tries to do a local delivery?
690
691A0036: 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
739Q0037: I am experiencing mailbox locking problems with Sun's \"mailtool"\ used
740 over a network.
741
742A0037: See Q9705 in the Sun-specific section below.
743
744
745Q0038: What does the error message \*error in forward file (filtering not
746 enabled): missing or malformed local part*\ mean?
747
748A0038: 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
759Q0039: I have installed Exim, but now I can't mail to \/root/\ any more. Why is
760 this?
761
762A0039: 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
775Q0040: How can I stop undeliverable bounce messages (e.g. to routeable, but
776 undeliverable, spammer senders) from clogging up the queue for days?
777
778A0040: 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
786Q0041: What does the message \*unable to set gid=ddd or uid=ddd (euid=ddd):
787 local delivery to ... transport=ttt*\ mean?
788
789A0041: 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 \(/etc/vfstab)\,
794 depending on your OS).
795
796
797Q0042: My ISP's mail server is rejecting bounce messages from Exim, complaining
798 that they have no sender. The SMTP trace does indeed show that the
799 sender address is \"<>"\. Why is the Sender on the bounce message empty?
800
801A0042: Because the RFCs say it must be. Your ISP is at fault. Send them this
802 extract from RFC 2821 section 6.1 (\*Reliable Delivery and Replies by
803 Email*\):
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
818Q0043: What does the error \*Unable to get interface configuration: 22 Invalid
819 argument*\ mean?
820
821A0043: 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
829Q0044: What does the error \*Failed to create spool file*\ mean?
830
831A0044: 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
862Q0045: 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
867A0045: 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
878Q0046: A short time after I start Exim I see a defunct zombie process. What
879 is causing this?
880
881A0046: 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
889Q0047: 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
893A0047: \-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
906Q0048: Whenever exim restarts it takes up to 3-5 minutes to start responding on
907 the SMTP port. Why is this?
908
909A0048: Something else is hanging onto port 25 and not releasing it. One place
910 to look is \(/etc/inetd.conf)\ in case for any reason an SMTP stream is
911 configured there.
912
913
914Q0049: What does the log message \*no immediate delivery: more than 10 messages
915 received in one connection*\ mean?
916
917A0049: A remote MTA sent a number of messages in a single SMTP session. Exim
918 limits the number of immediate delivery processes it creates as a
919 result of a single SMTP connection, in order to avoid creating a zillion
920 processes on systems that can have many incoming connections. If you are
921 dialing in to collect mail from your ISP, you should probably set
922 \smtp_accept_queue_per_connection\ to some number larger than 10, or
923 arrange to start a queue runner for local delivery (using \-ql-\)
924 immediately after collecting the mail.
925
926
927Q0050: 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
931A0050: See \smtp_accept_max\, \smep_accept_max_per_host\ and \smtp_accept_reserve\.
932
933
934Q0051: 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
938A0051: Use the \-bF-\ option to test system filters. This gives you access to the
939 freeze and fail actions.
940
941
942Q0052: What does \*ridiculously long message header*\ in an error report mean?
943
944A0052: 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 \(Local/Makefile)\ before building Exim. Exceeding the limit provokes
952 the ``ridiculous'' error message.
953
954
955Q0053: Exim on my host responds to a connection with \"220 *****..."\ and
956 won't understand \\EHLO\\ commands.
957
958A0053: This is the sign of a Cisco Pix ``Mailguard'' sitting in front of your
959 MTA. Pix breaks ESMTP and only does SMTP. It is a nuisance when you have
960 a secure MTA running on your box. Something like ``no fixup protocol
961 smtp 25'' in the Pix configuration is needed. It may be possible to do
962 this by logging into the Pix (using \^telnet^\ or \^ssh^\) 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
969Q0054: 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
973A0054: You have probably forgotten to quote a replacement string that contains
974 white space.
975
976
977Q0055: What does the error \*Failed to open wait-remote_smtp database: Invalid
978 argument*\ mean?
979
980A0055: 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
991Q0056: 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
996A0056: 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
1001Q0057: 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
1004A0057: 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
1013Q0058: What does the error \*failed to open DB file \(/var/spool/exim/db/retry)\:
1014 File exists*\ mean?
1015
1016A0058: 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
1029Q0059: 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
1047A0059: 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
1053Q0060: 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
1058A0060: 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
1063Q0061: What does the error \*Too many ``Received'' headers - suspected mail
1064 loop*\ mean?
1065
1066A0061: 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
1079Q0062: 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
1083A0062: 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
1092Q0063: When I try to start an Exim daemon, nothing happens. There is no
1093 process, and nothing is written to the Exim log.
1094
1095A0063: 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
1102Q0064: 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
1106A0064: 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 \(/usr/lib/sendmail)\.) The
1113 output should be something like this:
1114
1115==> Exim version 4.05 #1 built 13-Jun-2002 10:27:15
1116 Copyright (c) University of Cambridge 2002
1117
1118 If you don't see this, your Exim installation isn't fully operational.
1119 If you are running FreeBSD, see Q9201. For other systems, see Q0114.
1120
1121
1122Q0065: When (as \/root/\) 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
1126A0065: 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
1148Q0066: What does the message \*unable to set gid=xxx or uid=xxx*\ mean?
1149
1150A0066: 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
1183Q0067: What does the error \*too many unrecognized commands*\ mean?
1184
1185A0067: 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
1194Q0068: 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
1197A0068: 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
1213Q0069: What does the error \*SMTP data timeout (message abandoned) on connection
1214 from...*\ mean?
1215
1216A0069: 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
1233Q0070: What does the error \*SMTP command timeout on connection from...*\ mean?
1234
1235A0070: 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
1239Q0071: What does the error \*failed to open DB file \(/var/spool/exim//db/retry)\:
1240 Illegal argument*\ mean?
1241
1242A0071: See Q0058. The cause of this error is usually the same.
1243
1244
1245Q0072: 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
1249A0072: 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
1265Q0073: I'm seeing log file corruption, with parts of log lines getting mangled
1266 by other log entries.
1267
1268A0073: 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
1273Q0074: What does the error message \*remote delivery process count got out of
1274 step*\ mean?
1275
1276A0074: 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
1285Q0075: I'm using LDAP, and some email addresses that contain special characters
1286 are causing parsing errors in my LDAP lookups.
1287
1288A0075: You should be using \"${quote_ldap:$local_part}"\ instead of just
1289 \"$local_part"\ in your lookups.
1290
1291
1292Q0076: 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
1296A0076: 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
1307Q0077: 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
1311A0077: See Q5021.
1312
1313
1314Q0078: Exim is logging the unknown SMTP command \"XXXX"\ from my client hosts,
1315 and they are unable to authenticate.
1316
1317A0078: 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
1322Q0079: Our new PIX firewall is causing problems with incoming mail. How can
1323 this be fixed?
1324
1325A0079: See Q0053 and Q0078. If some messages get through and others do not,
1326 see also Q0017.
1327
1328
1329Q0080: 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
1333A0080: 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
1383Q0081: What does \*error in redirect data: included file xxxx is too big*\
1384 mean?
1385
1386A0081: 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
1402Q0082: 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
1406A0082: You have updated \^glibc^\ while an Exim daemon is running. Stop and
1407 restart the daemon.
1408
1409
1410Q0083: 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
1414A0083: 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
1429Q0084: 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
1433A0084: 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
1444Q0085: 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
1448A0085: 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
1456Q0086: What does \*SMTP protocol violation: synchronization error (next input
1457 sent too soon)*\ mean?
1458
1459A0086: 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
1471Q0087: 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
1475A0087: 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
1496Q0088: 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
1500A0088: 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
1517Q0089: What does the error \*kernel: application bug: exim(12099) has SIGCHLD
1518 set to SIG_IGN but calls wait()*\ mean?
1519
1520A0089: 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
1540Q0090: I can't seem to get a pipe command to run when I include a \"${lookup"\
1541 expansion in it.
1542
1543A0090: See Q0025.
1544
1545
1546Q0091: 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
1550A0091: See Q0065.
1551
1552
2683a02a
PH
1553Q0092: Exim crashes when I try to start the daemon, but works fine otherwise.
1554
1555A0092: 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
1568Q0093: The error message \*Program received signal SIGINT, Interrupt.*\ occurs
1569 when I try to use Exim with PostgreSQL.
1570
1571A0093: 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
15811. BUILDING AND INSTALLING
1582
1583Q0101: I'm having a problem with an Exim RPM.
1584
1585A0101: 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
1616Q0102: I can't get Exim to compile with Berkeley DB version 2.x or 3.x.
1617
1618A0102: 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
1624Q0103: 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
1628A0103: You should either remove the definition of \\USE_TCP_WRAPPERS\\ or add
1629 \"-lwrap"\ to your \\EXTRALIBS\\ setting in Local/Makefile.
1630
1631
1632Q0104: 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
1635A0104: 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
1649Q0105: What does the error \*install-info: command not found*\ mean?
1650
1651A0105: 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
1658Q0106: Exim doesn't seem to be recognizing my operating system type correctly,
1659 and so is failing to build.
1660
1661A0106: 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
1678Q0107: Exim fails to build, complaining about the absence of the \"killpg"\
1679 function.
1680
1681A0107: 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
1691Q0108: I'm getting an unresolved symbol \"ldap_is_ldap_url"\ when trying to build
1692 Exim.
1693
1694A0108: 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
1699Q0109: I'm getting an unresolved symbol \"mysql_close"\ when trying to build Exim.
1700
1701A0109: 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
1706Q0110: 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
1714A0110: Add \"-ldl"\ to \\EXTRALIBS\\. In some systems these dynamic loading functions
1715 are in their own library.
1716
1717
1718Q0111: I'm getting the error \*db.h: No such file or directory*\ when I try to
1719 build Exim.
1720
1721A0111: 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
1729Q0112: I'm getting the error \*/usr/bin/ld: cannot find -ldb*\ when I try to
1730 build Exim.
1731
1732A0112: This is probably the same problem as Q0111.
1733
1734
1735Q0113: 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
1739A0113: 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
1758Q0114: 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
1761A0114: 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
1775Q0115: What does \*Can't open \(../scripts/newer)\: No such file or directory*\
1776 mean? I got it while trying to build Exim.
1777
1778A0115: 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
1806Q0116: I have tried to build Exim with Berkeley DB 3 and 4, but I always get
1807 errors.
1808
1809A0116: 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
1834Q0117: Is there a quick walk-through of an Exim install from source anywhere?
1835
1836A0117: 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
1922Q0118: 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
1925A0118: 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
1935Q0119: I know there are some 3rd-party patches for Exim, for exiscan and
1936 other things. Where are they?
1937
1938A0119: 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
19532. ROUTING IN GENERAL
1954
1955Q0201: How can I arrange that messages larger than some limit are handled by
1956 a special router?
1957
1958A0201: You can use a \condition\ option on the router line this:
1959
1960==> condition = ${if >{$message_size}{100K}{yes}{no}}
1961
1962
1963Q0202: Can I specify a list of domains to explicitly reject?
1964
1965A0202: 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
1987Q0203: 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
1990A0203: 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
2004Q0204: 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
2008A0204: 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
2021Q0205: 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
2024A0205: 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
2043Q0206: How can I get Exim to deliver certain domains to a different SMTP port
2044 on my local host?
2045
2046A0206: 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
2063Q0207: Why does Exim lower-case the local-part of a non-local domain when
2064 routing?
2065
2066A0207: 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
20733. ROUTING TO REMOTE HOSTS
2074
2075Q0301: What do \*lowest numbered MX record points to local host*\ and \*remote
2076 host address is the local host*\ mean?
2077
2078A0301: 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
2133Q0302: Why does Exim say \*all relevant MX records point to non-existent hosts*\
2134 when MX records point to IP addresses?
2135
2136A0302: 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
2148Q0303: 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
2151A0303: 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
2159Q0304: How do I configure Exim to send all non-local mail to a gateway host?
2160
2161A0304: 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
2174Q0305: 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
2179A0305: 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
2200Q0306: 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
2204A0306: 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
2211Q0307: The \route_list\ setting \"^foo$:^bar$ $domain"\ in a \%manualroute%\
2212 router does not work.
2213
2214A0307: The first thing in a \route_list\ item is a single pattern, not a list of
2215 patterns. You need to write that as \"^(foo|bar)$ $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
2224Q0308: 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
2227A0308: 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
2253Q0309: 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
2258A0309: 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
2282Q0310: If a DNS lookup returns no MX records why doesn't Exim just bin the
2283 message?
2284
2285A0310: 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
2292Q0311: 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
2295A0311: 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
2305Q0312: 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$\N} \
2310 {<smarthost1>}{<smarthost2>}
2311
2312A0312: The problem is that the second item in \route_list\ contains white
2313 space, which means that it gets terminated prematurely. To avoid this,
2314 you must put the second item in quotes:
2315
2316==> route_list = * "${if match{$header_from:}{\N.*\.usa\.net$\N} \
2317 {<smarthost1>}{<smarthost2>}}"
2318
2319
2320Q0313: 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
2323A0313: 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
2334Q0314: 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
2340A0314: 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
2352Q0315: I'd like route all mail with addresses that can't be resolved (the DNS
2353 lookup times out) to a relay machine.
2354
2355A0315: 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
2359Q0316: I would like to forward all incoming email for a particular domain to
2360 another host via SMTP. Whereabouts would I configure that?
2361
2362A0316: 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
2375Q0317: 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
2378A0317: 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
2393Q0318: Exim won't route to a host with no MX record.
2394
2395A0318: 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
2430Q0319: 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
2434A0319: 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
2469Q0320: How can I arrange for all mail to \*user@some.domain*\ to be forwarded
2470 to \*user@other.domain*\?
2471
2472A0320: 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
2480Q0321: 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
2483A0321: 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
2496Q0322: How can I reroute all messages bound for 192.168.10.0 and 10.0.0.0 to
2497 a specific mail server?
2498
2499A0322: 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
25054. ROUTING FOR LOCAL DELIVERY
2506
2507Q0401: 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
2511A0401: 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
2534Q0402: 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
2538A0402: 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
2557Q0403: How do I configure Exim to send messages for unknown local users to a
2558 central server?
2559
2560A0403: 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
2575Q0404: How can I arrange for messages submitted by (for example) Majordomo to
2576 be handled specially?
2577
2578A0404: 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
2588Q0405: 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
2592A0405: 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
2606Q0406: 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
2609A0406: 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
2626Q0407: How can I arrange for a default value when using a query-style lookup
2627 such as LDAP or NIS+ to handle aliases?
2628
2629A0407: 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
2644Q0408: 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
2648A0408: Set the \qualify_preserve_domain\ option on the \%redirect%\ router.
2649
2650
2651Q0409: I want mail for any local part at certain virtual domains to go
2652 to a single address for each domain.
2653
2654A0409: 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
2671Q0410: How can I make Exim look in the alias NIS map instead of \(/etc/aliases)\?
2672
2673A0410: 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
2687Q0411: 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
2691A0411: 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
2700Q0412: 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
2704A0412: 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
2709Q0413: 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
2714A0413: 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
2751Q0414: 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
2756A0414: 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
2786Q0415: 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
2789A0415: 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
2794Q0416: 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
2798A0416: 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
2820Q0417: 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
2824A0417: 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 \(/usr/ucb/vacation)\ at all.
2861
2862
2863Q0418: I want to use a default entry in my alias file to handle unknown local
2864 parts, but it picks up the local parts that the aliases generate. For
2865 example, if the alias file is
2866
2867==> luke.skywalker: luke
2868 ls: luke
2869 *: postmaster
2870
2871 then messages addressed to \/luke.skywalker/\ end up at \/postmaster/\.
2872
2873A0418: The default mechanism works best with virtual domains, where the
2874 generated address is not in the same domain. If you just want to pick up
2875 all unknown local parts and send them to postmaster, an easier way to do
2876 it is to put this as your last router:
2877
2878==> unknown:
2879 driver = redirect
2880 data = postmaster
2881 no_verify
2882
2883 Another possibility is to put the redirect router for these aliases
2884 after all the other routers, so that local parts which are user names
2885 get picked off first. You will need to have two aliasing routers if
2886 there are some local parts (e.g. \/root/\) which are login names, but which
2887 you want to handle as aliases.
2888
2889
2890Q0419: 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
2893A0419: 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
2916Q0420: How can I arrange that mail addressed to \(anything@something.mydomain.com)\
2917 gets delivered to \(something@mydomain.com)\?
2918
2919A0420: 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
2927Q0421: I can't get a regular expression to work in a \local_parts\ option on
2928 one of my routers.
2929
2930A0421: 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
2937Q0422: 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
2940A0422: 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
2964Q0423: 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
2969A0423: 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
2998Q0424: 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
3001A0424: 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
3033Q0425: 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
3039A0425: 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
3070Q0426: 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
3074A0426: 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
3090Q0427: How can I have an address looked up in two different alias files, and
3091 delivered to all the addresses that are found?
3092
3093A0427: 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
3121Q0428: 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
3125A0428: 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
3141Q0429: 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
3144A0429: 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
3182Q0430: 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
3189A0430: Have you remembered to make Exim setuid \/root/\?
3190
3191
3192Q0431: How do I configure Exim to allow arbitrary extensions in local parts, of
3193 the form \/+extension/\?
3194
3195A0431: 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
3209Q0432: I use NIS for my user data. How can I stop Exim rejecting mail when my
3210 NIS servers are being restarted?
3211
3212A0432: 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
3239Q0433: How can I arrange for a single address to be processed by \*both*\
3240 \%redirect%\ \*and*\ \%accept%\?
3241
3242A0433: Check out the \unseen\ option.
3243
3244
3245Q0434: 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
3250A0434: 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
3296Q0435: My alias file contains fully qualified addresses as keys, and some
3297 wildcard domains in the form @foo.bar. Can Exim handle these?
3298
3299A0435: 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
33225. FILTERING
3323
3324Q0501: My filter isn't working. How can I test it?
3325
3326A0501: 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
3331Q0502: 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
3335A0502: 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 \"${run"\ expansion item to run an
3343 external command while filtering. In this case, you can make use of some
3344 of the results of the command.
3345
3346
3347Q0503: I received a message with a ::Subject:: line that contained a non-printing
3348 character (a carriage return). This messed up my filter file. Is there a
3349 way to get round it?
3350
3351A0503: Instead of \"$h_subject:"\ use \"${escape:$h_subject:}"\
3352
3353
3354Q0504: I want to search for \"$"\ in the subject line, but I can't seem to get
3355 the syntax.
3356
3357A0504: Try one of these:
3358
3359==> if $h_subject: contains \$ then ...
3360 if $h_subject: contains "\\$" then ...
3361
3362
3363Q0505: My problem is that Exim replaces \$local_part$\ with an empty string in the
3364 system filtering. What's wrong or what did I miss?
3365
3366A0505: A message may have many recipients. The system filter is run just once
3367 at the start of a delivery attempt. Consequently, it does not make sense
3368 to set \$local_part$\. 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$\.
3371
3372
3373Q0506: Using \$recipients$\ in a system filter gives me another problem: how can
3374 I do a string lookup if \$recipients$\ is a list of addresses?
3375
3376A0506: 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
3381Q0507: What are the main differences between using an Exim filter and using
3382 \^procmail^\?
3383
3384A0507: 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 ``\(.forward)\ file with conditions''. One of the benefits is de-duplication.
3387 Another is that if you forward, you are forwarding the original message.
3388
3389 However, this does mean that pipes etc. are not run at filtering time,
3390 nor can you change the headers, because the message may have other
3391 recipients and Exim keeps only a single set of headers.
3392
3393 \^procmail^\ runs at delivery time. This is for one recipient only, and so
3394 it can change headers, run pipes and check the results, etc. However, if
3395 it wants to forward, it has to create a new message containing a copy
3396 of the original message.
3397
3398 It's your choice as to which of these you use. You can of course use
3399 both.
3400
3401
3402Q0508: How can I allow the use of relative paths in users' filter files when
3403 the directories concerned are not available from the password data?
3404
3405A0508: You need to be running Exim 4.11 or later. You can then specify a value
3406 for \$home$\ by setting the router_home_directory option on the
3407 \%redirect%\ router.
3408
3409 For earlier releases, there is no way to specify the value of \$home$\
3410 for a \%redirect%\ router; it either comes from the password data as a
3411 result of \check_local_user\, or is unset.
3412
3413
3414Q0509: How can I set up a filter file to detect and block virus attachments?
3415
3416A0509: Exim's filter facilities aren't powerful enough to do much more than
3417 very crude testing. Most people that want virus checking are nowadays
3418 using one of the separate scanning programs such as \^exiscan^\ (see
3419 \?http://duncanthrax.net/exiscan/?\). There is some further information
3420 about scanning with Exim via \?http://www.timj.co.uk/linux/exim.php?\.
3421
3422
3423Q0510: Is it possible to write code for scanning messages in Python?
3424
3425A0510: \^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
3432Q0511: 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
3436A0511: 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
3454Q0512: I'm trying to reference the ::Envelope-To:: header in my filter, but
3455 \$h_envelope-to:$\ is always empty.
3456
3457A0512: ::Envelope-To:: is added at delivery time, by the transport. Therefore,
3458 the header doesn't exist at filter time. In a user filter, the values
3459 you probably want are in \$original_local_part$\ and
3460 \$original_domain$\. In a system filter, the complete list of all
3461 envelope recipients is in \$recipients$\.
3462
3463
3464Q0513: 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$\ in a system filter.
3467
3468A0513: You cannot do this in a system filter, because a single message may have
3469 multiple recipients, some in the special domain, and some not. That is
3470 also the reason why \$domain$\ 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
3488Q0514: 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
3492A0514: 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
35056. DELIVERY
3506
3507Q0601: What does the error \*Neither the xxx router nor the yyy transport set
3508 a uid for local delivery of...*\ mean?
3509
3510A0601: 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
3549Q0602: 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
3553A0602: 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
3582Q0603: 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
3585A0603: 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
3593Q0604: I want to use MMDF-style mailboxes. How can I get Exim to append the
3594 ctrl-A characters that separate indvidual emails?
3595
3596A0604: 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
3614Q0605: 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
3617A0605: 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
3633Q0606: 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
3637A0606: 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
3661Q0607: 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
3665A0607: 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
3691Q0608: 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
3694A0608: 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
3728Q0609: 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
3732A0609: 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
3750Q0610: How can I force the next retry time for a host to be now?
3751
3752A0610: 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
3762Q0611: I set up \"|/bin/grep Subject|/usr/bin/smbclient -M <netbiosname>"\ as an
3763 alias but it doesn't work.
3764
3765A0611: 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
3772Q0612: Why does the \%pipe%\ transport add a line starting with \">From"\ to
3773 messages?
3774
3775A0612: 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
3804Q0613: 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
3807A0613: \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
3813Q0614: 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
3817A0614: 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
3823Q0615: 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
3828A0615: 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
3835Q0616: Can Exim add a ::Content-Length:: header to messages it delivers?
3836
3837A0616: 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
3848Q0617: 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
3856A0617: 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
3871Q0618: 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
3874A0618: 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
3881Q0619: 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
3885A0619: 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
3890Q0620: 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
3894A0620: 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
3903Q0621: 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
3907A0621: 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
3922Q0622: 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
3925A0622: 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
3936Q0623: My \(/var/spool/mail)\ has grown drastically. Is there any possibility of
3937 using two directories?
3938
3939A0623: 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
3949Q0624: 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
3952A0624: Check out the \allow_commands\ option in the \%pipe%\ transport.
3953
3954
3955Q0625: I wish to have large emails go out one at a time.
3956
3957A0625: 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
3976Q0626: 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
3979A0626: 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