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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
65Last update: 31-March-2004
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
1553
15541. BUILDING AND INSTALLING
1555
1556Q0101: I'm having a problem with an Exim RPM.
1557
1558A0101: Normally the thing to do if you have a problem with an RPM package is
1559 to contact the person who built the package first, not the person who
1560 made the software that's in the package. You can usually find out who
1561 made a package using the following command:
1562
1563==> rpm --query --package --queryformat '%{PACKAGER}\n' <rpm-package-file>
1564
1565 where \[rpm-package-file]\ is the actual file, e.g. \(exim-3.03-2.i386.rpm)\.
1566 Or, if the package is installed on your system:
1567
1568==> rpm --query --queryformat '%{PACKAGER}\n' <package-name>
1569
1570 where \[package-name]\ is the name component of the package, e.g. \"exim"\.
1571 If the packager is unable or unwilling to help, only then should you
1572 contact the actual author or associated mailing list of the software.
1573
1574 If you discover through the querying process that you can't tell who
1575 the person (or company or group) is who built the package, or that they
1576 no longer exist at the given address, then you should reconsider
1577 whether you want a package from an unknown source on your system.
1578
1579 If you discover through the querying process that you yourself are the
1580 person who built the package, then you should either (a) contact the
1581 author or associated mailing list, or (b) reconsider whether you ought
1582 to be building and distributing RPM packages of software you don't
1583 understand.
1584
1585 Similar rules of thumb govern other binary package formats, including
1586 debs, tarballs, and POSIX packages.
1587
1588
1589Q0102: I can't get Exim to compile with Berkeley DB version 2.x or 3.x.
1590
1591A0102: Have you set \"USE_DB=yes\" in \(Local/Makefile)\? This causes Exim to use the
1592 native interface to the DBM library instead of the compatibility
1593 interface, which needs a header called \(ndbm.h)\ that may not exist on your
1594 system.
1595
1596
1597Q0103: I'm getting an \*undefined symbol*\ error for \"hosts_ctl"\ when I try to
1598 build Exim. (On some systems this error is \*undefined reference to
1599 'hosts_ctl'*\.)
1600
1601A0103: You should either remove the definition of \\USE_TCP_WRAPPERS\\ or add
1602 \"-lwrap"\ to your \\EXTRALIBS\\ setting in Local/Makefile.
1603
1604
1605Q0104: I'm about to upgrade to a new Exim release. Do I need to ensure the
1606 spool is empty, or take any other special action?
1607
1608A0104: It depends on where you are coming from.
1609
1610 (1) If you are changing to release 4.00 or later from a release prior to
1611 4.00, you will need to make changes to the run time configuration file.
1612 See the file \(doc/Exim4.upgrade)\ for details. If you are coming from
1613 before release 3.00, you should also see \(doc/Exim3.upgrade)\.
1614
1615 (2) If you are upgrading from an Exim 4 release to a later release, you
1616 do not need to take special action. New releases are made backwards
1617 compatible with old spool files and hints databases, so that upgrading
1618 can be done on a running system. All that should be necessary is to
1619 install a new binary and then HUP the daemon.
1620
1621
1622Q0105: What does the error \*install-info: command not found*\ mean?
1623
1624A0105: You have set \\INFO_DIRECTORY\\ in your \(Local/Makefile)\, and Exim is trying
1625 to install the Texinfo documentation, but cannot find the command called
1626 \(install-info)\. If you have a version of Texinfo prior to 3.9, you
1627 should upgrade. Otherwise, check your installation of Texinfo to see why
1628 the \(install-info)\ command is not available.
1629
1630
1631Q0106: Exim doesn't seem to be recognizing my operating system type correctly,
1632 and so is failing to build.
1633
1634A0106: Run the command \"scripts/os-type -generic"\. The output should be one of
1635 the known OS types, and should correspond to your operating system. You
1636 can see which OS are supported by obeying \"ls OS/Makefile-*"\ and looking
1637 at the file name suffixes.
1638
1639 If there is a discrepancy, it means that the script is failing to
1640 interpret the output from the \"uname"\ command correctly, or that the
1641 output is wrong. Meanwhile, you can build Exim by obeying
1642
1643==> EXIM_OSTYPE=xxxx make
1644
1645 instead of just \"make"\, provided you are running a Bourne-compatible
1646 shell, or otherwise by setting \\EXIM_OSTYPE\\ correctly in your
1647 environment. It is probably best to start again from a clean
1648 distribution, to avoid any wreckage left over from the failed attempt.
1649
1650
1651Q0107: Exim fails to build, complaining about the absence of the \"killpg"\
1652 function.
1653
1654A0107: This function should be present in all modern flavours of Unix. If you
1655 are using an older version, you should be able to get round the problem
1656 by inserting
1657
1658==> #define killpg(pgid,sig) kill(-(pgid),sig)
1659
1660 into the file called \(OS/os.h-xxx)\, where xxx identifies your operating
1661 system, and is the output of the command \"scripts/os-type -generic"\.
1662
1663
1664Q0108: I'm getting an unresolved symbol \"ldap_is_ldap_url"\ when trying to build
1665 Exim.
1666
1667A0108: You must have specified \"LOOKUP_LDAP=yes"\ in the configuration. Have you
1668 remembered to set \"-lldap"\ somewhere (e.g. in \\LOOKUP_LIBS\\)? You need that
1669 in order to get the LDAP library scanned when linking.
1670
1671
1672Q0109: I'm getting an unresolved symbol \"mysql_close"\ when trying to build Exim.
1673
1674A0109: You must have specified \"LOOKUP_MYSQL=yes"\ in the configuration. Have you
1675 remembered to set \"-lmysqlclient"\ somewhere (e.g. in \\LOOKUP_LIBS\\)? You
1676 need that in order to get the MySQL library scanned when linking.
1677
1678
1679Q0110: I'm trying to build Exim with PAM support. I have included \"-lpam"\ in
1680 \\EXTRALIBS\\, but I'm still getting a linking error:
1681
1682==> /lib/libpam.so: undefined reference to `dlerror'
1683 /lib/libpam.so: undefined reference to `dlclose'
1684 /lib/libpam.so: undefined reference to `dlopen'
1685 /lib/libpam.so: undefined reference to `dlsym'
1686
1687A0110: Add \"-ldl"\ to \\EXTRALIBS\\. In some systems these dynamic loading functions
1688 are in their own library.
1689
1690
1691Q0111: I'm getting the error \*db.h: No such file or directory*\ when I try to
1692 build Exim.
1693
1694A0111: This problem has been seen with RedHat 7.0, but could also happen in
1695 other environments. If your system is using the DB library, you
1696 need to install the DB development package in order to build Exim.
1697 The package is called something like \"db3-devel-3.1.14-16.i386.rpm"\ for
1698 Linux systems, but you should check which version of DB you have
1699 installed (current releases are DB 4).
1700
1701
1702Q0112: I'm getting the error \*/usr/bin/ld: cannot find -ldb*\ when I try to
1703 build Exim.
1704
1705A0112: This is probably the same problem as Q0111.
1706
1707
1708Q0113: I've compiled Exim and I've managed to start it but there was one
1709 problem - it always complained that \(libmsqlclient.so.10)\ was not found,
1710 even though this file is in \(/usr/local/lib/mysql/)\.
1711
1712A0113: Solaris: ensure you have this in your \(Local/Makefile)\:
1713
1714==> LOOKUP_LIBS=-L/usr/local/lib/mysql -R/usr/local/lib/mysql
1715
1716 Net/Open/FreeBSD: Run this command (or ensure it gets run automatically
1717 at boot time):
1718
1719==> ldconfig -m /usr/local/lib/mysql
1720
1721 Linux: add \(/usr/local/lib/mysql)\ to \(/etc/ld.so.conf)\ and re-run \(ldconfig)\.
1722 Alternatively, add
1723
1724==> -Wl,-rpath -Wl,/usr/local/lib/mysql
1725
1726 to EXTRA_LIBS and then re-link (this is similar to the Solaris solution
1727 above). This will probably also work on other systems that use GNU
1728 Binutils.
1729
1730
1731Q0114: How can I remove Sendmail from my system? I've built Exim and run \"make
1732 install"\, but it still doesn't seem to be fully operational.
1733
1734A0114: If you are running FreeBSD, see Q9201. Otherwise, you need to arrange
1735 that whichever of the paths \(/usr/sbin/sendmail)\ or \(/usr/lib/sendmail)\
1736 exists on your system is changed to refer to Exim. For example, you
1737 could use these commands (as \/root/\):
1738
1739==> mv /usr/sbin/sendmail /usr/sbin/sendmail.original
1740 chmod u-s /usr/sbin/sendmail.original
1741 ln -s /path/to/exim /usr/sbin/sendmail
1742
1743 The second command removes the setuid privilege from the old MTA, as a
1744 general safety precaution. In the third command, substitute the actual
1745 path to the Exim binary for \(/path/to/exim)\.
1746
1747
1748Q0115: What does \*Can't open \(../scripts/newer)\: No such file or directory*\
1749 mean? I got it while trying to build Exim.
1750
1751A0115: You are using FreeBSD, or another OS that has a \^make^\ command which
1752 tries to optimize the running of commands. Exim's \(Makefile)\ contains
1753 targets with sequential commands like this:
1754
1755==> buildpcre:
1756 @cd pcre; $(MAKE) SHELL=$(SHELL) AR="$(AR)" $(MFLAGS) CC="$(CC)" \
1757 CFLAGS="$(CFLAGS) $(PCRE_CFLAGS)" \
1758 RANLIB="$(RANLIB)" HDRS="$(PHDRS)" \
1759 INCLUDE="$(INCLUDE) $(IPV6_INCLUDE) $(TLS_INCLUDE)"
1760 @if $(SHELL) $(SCRIPTS)/newer pcre/libpcre.a exim; then \
1761 /bin/rm -f exim eximon.bin; fi
1762
1763 The second command assumes that the \"cd pcre"\ in the first command is
1764 no longer in effect. If you have \"-j3"\ in your default set of
1765 \"MAKEFLAGS"\, FreeBSD \^make^\ tries to optimize, and ends up up with both
1766 commands in the same shell process. The result is that \"$(SCRIPTS)"\
1767 (which has a value of \"../scripts"\) is not found.
1768
1769 The simplest solution is to force \^make^\ to use backwards compatibility
1770 mode with each command in its own shell, by using the \-B\ flag. To
1771 ensure that this happens throughout the build, it's best to export it in
1772 your environment:
1773
1774==> MAKEFLAGS='-B'
1775 export MAKEFLAGS
1776 make
1777
1778
1779Q0116: I have tried to build Exim with Berkeley DB 3 and 4, but I always get
1780 errors.
1781
1782A0116: One common problem, especially when you have several different versions
1783 of BDB installed on the same host, is that the header files and library
1784 files for BDB are not in a standard place. You therefore need to tell
1785 Exim where they are, by setting INCLUDE and DBMLIB in your
1786 \(Local/Makefile)\. For example, I use this on my workstation when
1787 I want to build with DB 4.1:
1788
1789==> INCLUDE=-I/opt/local/include/db-4.1
1790 DBMLIB=/opt/local/lib/db-4.1/libdb.a
1791
1792 Specifying the complete library file like this will cause it to be
1793 statically linked with Exim. You'll have to check to see where these
1794 files are on your system. For example, on FreeBSD 5, the header is in
1795 \(/usr/local/include/db4)\ and the library is in \(/usr/local/lib)\ and
1796 called \(libdb4)\. In that environment, you could use:
1797
1798==> INCLUDE=-I/usr/local/include/db4
1799 DBMLIB=-L/usr/local/lib -ldb4
1800
1801 This time, DBMLIB is specifying the library directory (\(/usr/local/lib)\)
1802 and the name of the library (\(db4)\) separately. The name of the actual
1803 library file is \(/usr/local/lib/libdb4.something)\. If the library was
1804 compiled for dynamic linking, that will be used.
1805
1806
1807Q0117: Is there a quick walk-through of an Exim install from source anywhere?
1808
1809A0117: Here! This is a contribution from a RedHat user, somewhat edited. On
1810 other operating systems things may be slightly different, but the
1811 general approach is the same.
1812
1813 (1) Install the db needed for Exim. This needs to be done first if you
1814 don't have a DBM library installed. Go to \?http://www.sleepycat.com?\
1815 and download \(db-4.1.25.tar.gz)\, or whatever the current release is.
1816 Then:
1817
1818==> gunzip db-4.1.25.tar.gz
1819 tar -xvf db-4.1.25.tar
1820 cd db-4.1.25
1821 cd build_unix
1822 ../dist/configure
1823 make
1824 make install
1825
1826 (2) Add a user for use by Exim, unless you want to use an existing user
1827 such as \/mail/\:
1828
1829==> adduser exim
1830
1831 (3) Now you can prepare to build Exim. Go to \?http://www.exim.org?\ or
1832 one of its mirrors, or the master ftp site
1833 \?ftp://ftp.csx.cam.ac.uk/pub/software/email/exim/exim4?\, and download
1834 \(exim-4.20.tar.gz)\ or whatever the current release is. Then:
1835
1836==> gunzip exim-4.20.tar.gz
1837 tar -xvf exim-4.20.tar
1838 cd exim-4.20
1839 cp src/EDITME Local/Makefile
1840 cp exim_monitor/EDITME Local/eximon.conf
1841
1842 (4) Edit \(Local/Makefile)\:
1843
1844 Comment out EXIM_MONITOR= unless you want to install the Exim
1845 monitor (it requires X-windows).
1846
1847 Set the user you want Exim to use for itself:
1848
1849==> EXIM_USER=exim
1850
1851 If your DBM library is Berkeley DB, set up to use its native interface:
1852
1853==> USE_DB=yes
1854
1855 Make sure Exim's build can find the DBM library and its headers. If
1856 you've installed Berkeley DB 4 you'll need to have settings like this
1857 in \(Local/Makefile)\:
1858
1859==> INCLUDE=-I/usr/local/BerkeleyDB.4.1/include
1860 DBMLIB=/usr/local/BerkeleyDB.4.1/lib/libdb.a
1861
1862 (Check that the first directory contains the db.h file and that the
1863 second library exists.)
1864
1865 You don't need to change anything else, but you might want to review
1866 the default settings in the ``must specify'' section.
1867
1868 (4) Build Exim by running the \/make/\ command.
1869
1870 (5) Install Exim by running, as \/root/\:
1871
1872==> make install
1873
1874 You \*must*\ be \/root/\ to do this. You do not have to be root for any of
1875 the previous building activity.
1876
1877 (6) Run some tests on Exim; see if it will do local and remote
1878 deliveries. Change the configuration if necessary (for example,
1879 uncommenting \group\ on the \%local_delivery%\ transport if you don't
1880 use a ``sticky bit'' directory).
1881
1882 (7) Change Sendmail to Exim (of course you need to have had Sendmail
1883 installed to do this).
1884
1885==> /etc/init.d/sendmail stop
1886 mv /usr/sbin/sendmail /usr/sbin/sendmail.org
1887 ln -s /usr/exim/bin/exim /usr/sbin/sendmail
1888 /etc/init.d/sendmail start
1889
1890 (8) Check the Exim log. Either use the Exim monitor, or:
1891
1892==> tail -f /var/spool/exim/log/mainlog
1893
1894
1895Q0118: I've set \"LOOKUP_INCLUDE=-I/client/include"\ in Local/Makefile, but the
1896 compilation of \^exim_dumpdb^\ is ignoring this option and failing. Why?
1897
1898A0118: LOOKUP_INCLUDE is the special include file for lookup modules in Exim
1899 (e.g. mysql, LDAP). Confusingly, it doesn't apply to basic DBM code
1900 which is used also for other things. Try setting INCLUDE and DBMLIB
1901 instead. For example:
1902
1903==> USE_DB=yes
1904 INCLUDE=-I/client/include
1905 DBMLIB=/client/lib/libdb.a
1906
1907
1908Q0119: I know there are some 3rd-party patches for Exim, for exiscan and
1909 other things. Where are they?
1910
1911A0119: Exiscan is at \?http://duncanthrax.net/exiscan-acl/?\.
1912[[br]]
1913 Scanexi is at \?http://w1.231.telia.com/~u23107873/scanexi.html?\
1914[[br]]
1915 A sample \^^local_scan()^^\ function for interfacing to \^uvscan^\ is
1916 at \?http://www.dcs.qmul.ac.uk/~mb/local_scan/?\.
1917[[br]]
1918 An interface to SpamAssassin at SMTP time is at
1919 \?http://marc.merlins.org/linux/exim/sa.html?\.
1920[[br]]
1921 A mini-HOWTO (PDF file) about scanning and virus scanning, and some RPMs
1922 can be found at \?http://www.timj.co.uk/linux/exim.php?\.
1923
1924
1925
19262. ROUTING IN GENERAL
1927
1928Q0201: How can I arrange that messages larger than some limit are handled by
1929 a special router?
1930
1931A0201: You can use a \condition\ option on the router line this:
1932
1933==> condition = ${if >{$message_size}{100K}{yes}{no}}
1934
1935
1936Q0202: Can I specify a list of domains to explicitly reject?
1937
1938A0202: Set up a named domain list containing the domains in the first section
1939 of the configuration, for example:
1940
1941==> domainlist reject_domains = list:of:domains:to:reject
1942
1943 You can use this list in an ACL to reject any SMTP recipients in those
1944 domains. You can also give a customized error message, like this:
1945
1946==> deny message = The domain $domain is no longer supported
1947 domains = +reject_domains
1948
1949 If you also want to reject these domains in messages that are submitted
1950 from the command line (not using SMTP), you need to set up a router to
1951 do it, like this:
1952
1953==> reject_domains:
1954 driver = redirect
1955 domains = +reject_domains
1956 allow_fail
1957 data = :fail: The domain $domain is no longer supported
1958
1959
1960Q0203: How can I arrange to do my own qualification of non-fully-qualified
1961 domains, and then pass them on to the next router?
1962
1963A0203: If you have some list of domains that you want to qualify, you can do
1964 this using a redirect router. For example,
1965
1966==> qualify:
1967 driver = redirect
1968 domains = *.a.b
1969 data = ${quote:$local_part}@$domain.c.com
1970
1971 This adds \".c.com"\ to any domain that matches \"*.a.b"\.
1972 If you want to do this in conjunction with a \%dnslookup%\ router, the
1973 \widen_domains\ option of that router may be another way of achieving
1974 what you want.
1975
1976
1977Q0204: Every system has a \"nobody"\ account under which httpd etc run. I would
1978 like to know how to restrict mail which comes from that account to users
1979 on that host only.
1980
1981A0204: Set up a first router like this:
1982
1983==> fail_nobody:
1984 driver = redirect
1985 senders = nobody@your.domain
1986 domains = ! +local_domains
1987 allow_fail
1988 data = :fail: Nobody may not mail off-site
1989
1990 This assumes you have defined \+local_domains\ as in the default
1991 configuration.
1992
1993
1994Q0205: How can I get Exim to deliver to me locally and everyone else at the same
1995 domain via SMTP to the MX record specified host?
1996
1997A0205: Create an \%accept%\ router to pick off the one address and pass it to
1998 an appropriate transport. Put this router before the one that does MX
1999 routing:
2000
2001==> me:
2002 driver = accept
2003 domains = dom.com
2004 local_parts = me
2005 transport = local_delivery
2006
2007 In the transport you will have to specify the \user\ option. An
2008 alternative way of doing this is to add a condition to the router that
2009 does MX lookups to make it skip your address. Subsequent routers can then
2010 deliver your address locally. You'll need a condition like this:
2011
2012==> condition = \
2013 ${if and {{eq{$domain}{dom.com}}{eq{$local_part}{me}}}{no}{yes}}
2014
2015
2016Q0206: How can I get Exim to deliver certain domains to a different SMTP port
2017 on my local host?
2018
2019A0206: You must set up a special \%smtp%\ transport, where you can specify the
2020 \port\ option, and then set up a router to route the domains to that
2021 transport. There are two possibilities for specifying the host:
2022
2023 (1) If you use a \%manualroute%\ router, you can specify the local host
2024 in the router options. You must also set
2025
2026==> self = send
2027
2028 so that it does not object to sending to the local host.
2029
2030 (2) If you use a router that cannot specify hosts (for example, an
2031 \%accept%\ router with appropriate conditions), you have to specify
2032 the host using the \hosts\ option of the transport. In this case,
2033 you must also set \allow_localhost\ on the transport.
2034
2035
2036Q0207: Why does Exim lower-case the local-part of a non-local domain when
2037 routing?
2038
2039A0207: Because \caseful_local_part\ is not set (in the default configuration)
2040 for the \%dnslookup%\ router. This does not matter because the local
2041 part takes no part in the routing, and the actual local part that is
2042 sent out in the RCPT command is always the original local part.
2043
2044
2045
20463. ROUTING TO REMOTE HOSTS
2047
2048Q0301: What do \*lowest numbered MX record points to local host*\ and \*remote
2049 host address is the local host*\ mean?
2050
2051A0301: They mean exactly what they say. Exim expected to route an address to a
2052 remote host, but the IP address it obtained from a router was for the
2053 local host. If you really do want to send over TCP/IP to the local host
2054 (to a different version of Exim or another MTA, for example), see Q0206.
2055
2056 More commonly, these errors arise when Exim thinks it is routing some
2057 foreign domain. For example, the router configuration causes Exim to
2058 look up the domain in the DNS, but when Exim examines the DNS output,
2059 either the lowest numbered MX record points at the local host, or there
2060 are no MX records, and the address record for the domain contains an
2061 IP address that belongs to the local host.
2062
2063 There has been a rash of instances of domains being deliberately set up
2064 with MX records pointing to \"localhost"\ (or other names with A records
2065 that specify 127.0.0.1), which causes this behaviour. You can use the
2066 \ignore_target_hosts\ option to get Exim to ignore these records. The
2067 default contiguration does this. For more discussion, see Q0319. For
2068 other cases:
2069
2070 (1) If the domain is meant to be handled as a local domain, there
2071 is a problem with the configuration, because it should not then have
2072 been looked up in the DNS. Check the \domains\ settings on your
2073 routers.
2074
2075 (2) If the domain is one for which the local host is providing a
2076 relaying service (called ``mail hubbing''), possibly as part of a
2077 firewall, you need to set up a router to tell Exim where to send
2078 messages addressed to this domain, because the DNS directs them to
2079 the local host. You should put a router like this one before the one
2080 that does DNS lookups:
2081
2082==> hubbed_hosts:
2083 driver = manualroute
2084 transport = remote_smtp
2085 route_list = see discussion below
2086
2087 The contents of the \route_list\ option depend on how many hosts you
2088 are hubbing for, and how their names are related to the domain name.
2089 Suppose the local host is a firewall, and all the domains in
2090 \(*.foo.bar)\ have MX records pointing to it, and each domain
2091 corresponds to a host of the same name. Then the setting could be
2092
2093==> route_list = *.foo.bar $domain
2094
2095 If there isn't a convenient relationship between the domain names
2096 and the host names, you either have to list each domain separately,
2097 or use a lookup expansion to look up the host from the domain, or
2098 put the routing information in a file and use the \route_data\
2099 option with a lookup expansion.
2100
2101 (3) If neither (1) nor (2) is the case, the lowest numbered MX record or
2102 the address record for the domain should not be pointing to your
2103 host. You should arrange to get the DNS mended.
2104
2105
2106Q0302: Why does Exim say \*all relevant MX records point to non-existent hosts*\
2107 when MX records point to IP addresses?
2108
2109A0302: MX records cannot point to IP addresses. They are defined to point to
2110 host names, so Exim always interprets them that way. (An IP address is a
2111 syntactically valid host name.) The DNS for the domain you are having
2112 problems with is misconfigured.
2113
2114 However, it appears that more and more DNS zones are breaking the rules
2115 and putting IP addresses on the RHS of MX records. Exim follows the
2116 rules and rejects this, but other MTAs do support it, so the
2117 \allow_mx_to_ip\ was regretfully added at release 3.14 to permit this
2118 heinous activity.
2119
2120
2121Q0303: How do I configure Exim to send all messages to a central server? I
2122 don't want to do any local deliveries at all on this host.
2123
2124A0303: Use this as your first and only router:
2125
2126==> send_to_gateway:
2127 driver = manualroute
2128 transport = remote_smtp
2129 route_list = * central.server.host
2130
2131
2132Q0304: How do I configure Exim to send all non-local mail to a gateway host?
2133
2134A0304: Replace the \%dnslookup%\ router in the default configuration with the
2135 following:
2136
2137==> send_to_gateway:
2138 driver = manualroute
2139 domains = !+local_domains
2140 transport = remote_smtp
2141 route_list = * gate.way.host
2142
2143 If there are several hosts you can send to, you can specify them as a
2144 colon-separated list.
2145
2146
2147Q0305: How can I arrange for mail on my local network to be delivered directly
2148 to the relevant hosts, but all other mail to be sent to my ISP's mail
2149 server? The local hosts are all DNS-registered and behave like normal
2150 Internet hosts.
2151
2152A0305: Set up a first router to pick off all the domains for your local
2153 network. There are several ways you might do this. For example
2154
2155==> local_network:
2156 driver = dnslookup
2157 transport = remote_smtp
2158 domains = *.mydomain.com
2159
2160 This does a perfectly conventional DNS routing operation, but only for
2161 the domains that match \(*.mydomain.com)\. Follow this with a `smart
2162 host' router:
2163
2164==> internet:
2165 driver = manualroute
2166 domains = !+local_domains
2167 transport = remote_smtp
2168 route_list = * mail.isp.net
2169
2170 This routes any other non-local domains to the smart host.
2171
2172
2173Q0306: How do I configure Exim to send all non-local mail to a central server
2174 if it cannot be immediately delivered by my host? I don't want to have
2175 queued mail waiting on my host.
2176
2177A0306: Add to the \%remote_smtp%\ transport the following:
2178
2179==> fallback_hosts = central.server.name(s)
2180
2181 If there are several names, they must be separated by colons.
2182
2183
2184Q0307: The \route_list\ setting \"^foo$:^bar$ $domain"\ in a \%manualroute%\
2185 router does not work.
2186
2187A0307: The first thing in a \route_list\ item is a single pattern, not a list of
2188 patterns. You need to write that as \"^(foo|bar)$ $domain"\.
2189 Alternatively, you could use several items and write
2190
2191==> route_list = foo $domain; bar $domain
2192
2193 Note the semicolon separator. This is because the second thing in each
2194 item can itself be a list - of hosts.
2195
2196
2197Q0308: I have a domain for which some local parts must be delivered locally,
2198 but the remainder are to be treated like any other remote addresses.
2199
2200A0308: One possible way of doing this is as follows: Assuming you are using a
2201 configuration that is similar to the default one, first exclude your
2202 domain from the first router by changing it to look like this:
2203
2204==> non_special_remote:
2205 driver = dnslookup
2206 domains = ! +local_domains : ! special.domain
2207 transport = remote_smtp
2208 ignore_target_hosts = 127.0.0.0/8
2209 no_more
2210
2211 Then add a second router which handles the local parts that are not to
2212 be delivered locally:
2213
2214==> special_remote:
2215 driver = dnslookup
2216 domains = special.domain
2217 local_parts = ! lsearch;/list/of/special/localparts
2218 transport = remote_smtp
2219 ignore_target_hosts = 127.0.0.0/8
2220 no_more
2221
2222 The remaining local parts will fall through to the remaining routers,
2223 which can delivery them locally.
2224
2225
2226Q0309: How can I configure Exim on a firewall machine so that if mail arrives
2227 addressed to a domain whose MX points to the firewall, it is forwarded
2228 to the internal mail server, without having to have a list of all the
2229 domains involved?
2230
2231A0309: As your first router, have the standard \%dnslookup%\ router from the
2232 default configuration, with the added option
2233
2234==> self = pass
2235
2236 This will handle all domains whose lowest numbered MX records do not
2237 point to your host. Because of the \no_more\ setting, if it encounters
2238 an unknown domain, routing will fail. However, if it hits a domain whose
2239 lowest numbered MX points to your host, the \self\ option comes into
2240 play, and overrides \no_more\. The \"pass"\ setting causes it to pass
2241 the address on to the next router. (The default causes it to generate an
2242 error.)
2243
2244 The only non-local domains that reach the second router are those with
2245 MX records pointing to the local host. Set it up to send them to the
2246 internal mail server like this:
2247
2248==> internal:
2249 driver = manualroute
2250 domains = ! +local_domains
2251 transport = remote_smtp
2252 route_list = * internal.server
2253
2254
2255Q0310: If a DNS lookup returns no MX records why doesn't Exim just bin the
2256 message?
2257
2258A0310: If a DNS lookup returns no MXs, Exim looks for an address record, in
2259 accordance with the rules that are defined in the RFCs. If you want to
2260 break the rules, you can set \mx_domains\ in the \%dnslookup%\ router, but
2261 you will cut yourself off from those sites (and there still seem to be
2262 plenty) who do not set up MX records.
2263
2264
2265Q0311: When a DNS lookup for MX records fails to complete, why doesn't Exim
2266 send the messsage to the host defined by the A record?
2267
2268A0311: The RFCs are quite clear on this. Only if it is known that there are no
2269 MX records is an MTA allowed to make use of the A record. When an MX
2270 lookup fails to complete, Exim does not know whether there are any MX
2271 records or not. There seem to be some name servers (or some
2272 configurations of some name servers) that give a ``server fail'' error when
2273 asked for a non-existent MX record. Exim uses standard resolver calls,
2274 which unfortunately do not distinguish between this case and a timeout,
2275 so all Exim can do is try again later.
2276
2277
2278Q0312: Is it possible to use a conditional expression for the host item in a
2279 \route_list\ for \%manualroute%\ router? I tried the following, but it
2280 doesn't work:
2281
2282==> route_list = * ${if match{$header_from:}{\N.*\.usa\.net$\N} \
2283 {<smarthost1>}{<smarthost2>}
2284
2285A0312: The problem is that the second item in \route_list\ contains white
2286 space, which means that it gets terminated prematurely. To avoid this,
2287 you must put the second item in quotes:
2288
2289==> route_list = * "${if match{$header_from:}{\N.*\.usa\.net$\N} \
2290 {<smarthost1>}{<smarthost2>}}"
2291
2292
2293Q0313: I send all external mail to a smart host, but this means that bad
2294 addresses also get passed to the smart host. Can I avoid this?
2295
2296A0313: Assuming you have DNS availability, set up a conventional \%dnslookup%\
2297 router to do the routing, but in the \%remote_smtp%\ transport set this:
2298
2299==> hosts = your.smart.host
2300 hosts_override
2301
2302 This will override the hosts that the router finds so that everything
2303 goes to the smart host, but any non-existent domains will be failed by
2304 the router.
2305
2306
2307Q0314: I have a really annoying intermittent problem where attempts to mail to
2308 valid sites are rejected with \*unknown mail domain*\. This only happens a
2309 few times a day and there is no particular pattern to the sites it
2310 rejects. If I try to lookup the same domain a few minutes later then it
2311 is OK.
2312
2313A0314: This is almost certainly a problem with the DNS resolver or the the
2314 domain's name servers.
2315
2316 (1) Have you linked Exim against the newest DNS resolver library that
2317 comes with Bind? If you are using SunOS4 that may be your problem, as
2318 the resolver that comes with that OS is known to be buggy and to give
2319 intermittent false negatives.
2320
2321 (2) Effects like this are sometimes seen if a domain's name servers get
2322 out of step with each other.
2323
2324
2325Q0315: I'd like route all mail with addresses that can't be resolved (the DNS
2326 lookup times out) to a relay machine.
2327
2328A0315: Set \pass_on_timeout\ on your \%dnslookup%\ router, and add below it a
2329 \%manualroute%\ router that routes all relevant domains to the relay.
2330
2331
2332Q0316: I would like to forward all incoming email for a particular domain to
2333 another host via SMTP. Whereabouts would I configure that?
2334
2335A0316: Use this as your first router:
2336
2337==> special:
2338 driver = manualroute
2339 transport = remote_smtp
2340 route_list = the.particular.domain the.other.host
2341
2342 You will also need to adjust the ACL for incoming SMTP so that this
2343 domain is accepted for relaying. If you are using the default
2344 configuration, there is a domain list called \relay_domains\ that is
2345 set up for this.
2346
2347
2348Q0317: What I'd like to do is have alternative smart hosts, where the one to be
2349 used is determined by which ISP I'm connected to.
2350
2351A0317: The simplest way to do this is to arrange for the name of the smart host
2352 du jour to be placed in a file when you connect, say \(/etc/smarthost)\.
2353 Then you can read this file from a \%manualroute%\ router like this:
2354
2355==> smarthost:
2356 driver = manualroute
2357 transport = remote_smtp
2358 route_list = * ${readfile{/etc/smarthost}{}}
2359
2360 The second argument of the \"readfile"\ item is a string that replaces
2361 any newline characters in the file (in this case, with nothing).
2362 By keeping the data out of the main configuration file, you avoid having
2363 to HUP the daemon when it changes.
2364
2365
2366Q0318: Exim won't route to a host with no MX record.
2367
2368A0318: More than one thing may cause this.
2369
2370 (1) Are you sure there really is no MX record? Sometimes a typo results
2371 in a malformed MX record in the zone file, in which case some name
2372 servers give a SERVFAIL error rather than NXDOMAIN. Exim has to treat
2373 this as a temporary error, so it can't go on to look for address records.
2374 You can check for this state using one of the DNS interrogation commands,
2375 such as \(nslookup)\, \(host)\, or \(dig)\.
2376
2377 (2) Is there a wildcard MX record for \(your)\ domain? Is the
2378 \search_parents\ option on in your \%dnslookup%\ router? If the answer to
2379 both these questions is ``yes'', that is the cause of the problem. When
2380 the DNS resolver fails to find the MX record, it tries adding on your
2381 domain if \search_parents\ is true, and thereby finds your wildcard MX
2382 record. For example:
2383
2384 . There is a wildcard MX record for \(*.a.b.c)\.
2385
2386 . There is a host called \(x.y.z)\ that has an A record and no MX record.
2387
2388 . Somebody on the host \(m.a.b.c)\ domain tries to mail to \(user@x.y.z)\.
2389
2390 . Exim calls the DNS to look for an MX record for \(x.y.z)\.
2391
2392 . The DNS doesn't find any MX record. Because \search_parents\ is true,
2393 it then tries searching the current host's parent domain, so it
2394 looks for \(x.y.z.a.b.c)\ and picks up the wildcard MX record.
2395
2396 Setting \search_parents\ false makes this case work while retaining the
2397 wildcard MX record. However, anybody on the host \(m.a.b.c)\ who mails to
2398 \(user@n.a)\ (expecting it to go to \(user@n.a.b.c)\) now has a problem. The
2399 \widen_domains\ option of the \%dnslookup%\ router may be helpful in this
2400 circumstance.
2401
2402
2403Q0319: I have some mails on my queues that are sticking around longer than
2404 the retry time indicates they should. They are all getting frozen
2405 because some remote admin has set their MX record to 127.0.0.1.
2406
2407A0319: The admin in question is an idiot. Exim will always freeze such messages
2408 because they are apparently routed to the local host. To bounce these
2409 messages immediately, set
2410
2411==> ignore_target_hosts = 127.0.0.1
2412
2413 on the \%dnslookup%\ router. This causes Exim to completely ignore any hosts
2414 with that IP address. In fact, there are quite a number of IP addresses
2415 that should never be used. Here is a suggested configuration list for
2416 the IPv4 ones:
2417
2418==> # Don't allow domains whose single MX (or A) record is a
2419 # "special-use IPv4 address", as listed in RFC 3330.
2420 ignore_target_hosts = \
2421 # Hosts on "this network"; RFC 1700 (page 4) states that these
2422 # are only allowed as source addresses
2423 0.0.0.0/8 : \
2424 # Private networks, RFC 1918
2425 10.0.0.0/8 : 172.16.0.0/12 : 192.168.0.0/16 : \
2426 # Internet host loopback address, RFC 1700 (page 5)
2427 127.0.0.0/8 : \
2428 # "Link local" block
2429 169.254.0.0/16 : \
2430 # "TEST-NET" - should not appear on the public Internet
2431 192.0.2.0/24 : \
2432 # 6to4 relay anycast addresses, RFC 3068
2433 192.88.99.0/24 : \
2434 # Network interconnect device benchmark testing, RFC 2544
2435 198.18.0.0/15 : \
2436 # Multicast addresses, RFC 3171
2437 224.0.0.0/4 : \
2438 # Reserved for future use, RFC 1700 (page 4)
2439 240.0.0.0/4
2440
2441
2442Q0320: How can I arrange for all mail to \*user@some.domain*\ to be forwarded
2443 to \*user@other.domain*\?
2444
2445A0320: Put this as your first router:
2446
2447==> forward:
2448 driver = redirect
2449 domains = some.domain
2450 data = ${quote:$local_part}@other.domain
2451
2452
2453Q0321: How can I tell an Exim router to use only IPv4 or only IPv6 addresses
2454 when it finds both types in the DNS?
2455
2456A0321: You can do this by making it ignore the addresses you don't want. This
2457 example ignores all IPv6 addresses and all IPv4 addresses in the 127
2458 network:
2459
2460==> ignore_target_hosts = <; 0000::0000/0 ; 127.0.0.0/8
2461
2462 To ignore all IPv4 addresses, use
2463
2464==> ignore_target_hosts = 0.0.0.0/0
2465
2466 See Q0319 for a general discussion of \ignore_target_hosts\.
2467
2468
2469Q0322: How can I reroute all messages bound for 192.168.10.0 and 10.0.0.0 to
2470 a specific mail server?
2471
2472A0322: That is an odd requirement. However, there is an obscure feature in
2473 Exim, originally implemented for packet radio people, that perhaps can
2474 help. Check out the \translate_ip_address\ generic router option.
2475
2476
2477
24784. ROUTING FOR LOCAL DELIVERY
2479
2480Q0401: I need to have any mail for \(virt.dom.ain)\ that doesn't match one of the
2481 aliases in \(/usr/lib/aliases.virt)\ delivered to a particular address, for
2482 example, \(postmaster@virt.dom.ain)\.
2483
2484A0401: Adding an asterisk to a search type causes Exim to look up ``*'' when the
2485 normal lookup fails. So if your aliasing router is something like this:
2486
2487==> virtual:
2488 driver = redirect
2489 domains = virt.dom.ain
2490 data = ${lookup{$local_part}lsearch{/usr/lib/aliases.virt}}
2491 no_more
2492
2493 you should change \"lsearch"\ to \"lsearch*"\, and put this in the alias
2494 file:
2495
2496==> *: postmaster@virt.dom.ain
2497
2498 This solution has the feature that if there are several unknown
2499 addresses in the same message, only one copy gets sent to the
2500 postmaster, because of Exim's normal de-duplication rules.
2501
2502 NOTE: This solution works only if there is also an entry for \(postmaster)\
2503 in the alias file, ultimately resolving to an address that is not in
2504 \(virt.dom.ain)\. See also Q0434.
2505
2506
2507Q0402: How do I arrange for all incoming email for \(*@some.domain)\ to go into one
2508 pop3 mail account? The customer doesn't want to add a list of specific
2509 local parts to the system.
2510
2511A0402: Set up a special transport that writes to the mailbox like this:
2512
2513==> special_transport:
2514 driver = appendfile
2515 file = /pop/mailbox
2516 envelope_to_add
2517 return_path_add
2518 delivery_date_add
2519 user = exim
2520
2521 The file will be written as the user \"exim"\. Then arrange to route all
2522 mail for that domain to that transport, with a router like this:
2523
2524==> special_router:
2525 driver = accept
2526 domains = some.domain
2527 transport = special_transport
2528
2529
2530Q0403: How do I configure Exim to send messages for unknown local users to a
2531 central server?
2532
2533A0403: Assuming you are using something like the default configuration, where
2534 local users are processed by the later routers, you should add the
2535 following router at the end:
2536
2537==> unknown:
2538 driver = manualroute
2539 transport = remote_smtp
2540 route_list = * server.host.name
2541 no_verify
2542
2543 However, you should if possible try to verify that the user is known on
2544 the central server before accepting the message in the first place. This
2545 can be done by making use of Exim's ``call forward'' facility.
2546
2547
2548Q0404: How can I arrange for messages submitted by (for example) Majordomo to
2549 be handled specially?
2550
2551A0404: You can use the \condition\ option on a router, with a setting such as
2552
2553==> condition = ${if and {{eq {$sender_host_address}{}} \
2554 {eq {$sender_ident}{majordom}}} {yes}{no}}
2555
2556 This first tests for a locally-submitted message, by ensuring there is
2557 no sending host address, and then it checks the identity of the user
2558 that ran the submitting process.
2559
2560
2561Q0405: On a host that accepts mail for several domains, do I have to use fully
2562 qualified addresses in \(/etc/aliases)\ or do I have to set up an alias
2563 file for each domain?
2564
2565A0405: You can do it either way. The default aliasing router contains this line:
2566
2567==> data = ${lookup{$local_part}lsearch{/etc/aliases}}
2568
2569 which is what does the actual lookup. To make it look up the complete
2570 address instead of just the local part, use
2571
2572==> data = ${lookup{$local_part@$domain}lsearch{/etc/aliases}}
2573
2574 If you want to use a separate file for each domain, use
2575
2576==> data = ${lookup{$local_part}lsearch{/etc/aliases/$domain}}
2577
2578
2579Q0406: Some of my users are using the \(.forward)\ to pipe to a shell command which
2580 appends to the user's INBOX. How can I forbid this?
2581
2582A0406: If you allow your users to run shells in pipes, you cannot control which
2583 commands they run or which files they write to. However, you should point
2584 out to them that writing to an INBOX by arbitrary commands is not
2585 interlocked with the MTA and MUAs, and is liable to mess up the contents
2586 of the file.
2587
2588 If a user simply wants to choose a specific file for the delivery of
2589 messages, this can be done by putting a file name in a \(.forward)\ file
2590 rather than using a pipe, or by using the \"save"\ command in an Exim
2591 filter file.
2592
2593 You can set \forbid_pipe\ on the router, but that will prevent them from
2594 running any pipe commands at all. Alternatively, you can restrict which
2595 commands they may run in their pipes by setting the \allow_commands\
2596 and/or \restrict_to_path\ options in the \%address_pipe%\ transport.
2597
2598
2599Q0407: How can I arrange for a default value when using a query-style lookup
2600 such as LDAP or NIS+ to handle aliases?
2601
2602A0407: Use a second query in the failure part of the original lookup, like
2603 this:
2604
2605==> data = ${lookup ldap\
2606 {ldap://x.y.z/l=yvr?aliasaddress?sub?(&(mail=$local_part@$domain))}\
2607 {$value}\
2608 {\
2609 ${lookup ldap \
2610 {ldap://x.y.z/l=yvr?aliasaddress?sub?(&(mail=default@$domain))}}\
2611 }}
2612
2613 Of course, if the default is a fixed value you can just include it
2614 directly.
2615
2616
2617Q0408: If I don't fully qualify the addresses in a virtual domain's alias file
2618 then mail to aliases which also match the local domain get delivered to
2619 the local domain.
2620
2621A0408: Set the \qualify_preserve_domain\ option on the \%redirect%\ router.
2622
2623
2624Q0409: I want mail for any local part at certain virtual domains to go
2625 to a single address for each domain.
2626
2627A0409: One way to to this is
2628
2629==> virtual:
2630 driver = redirect
2631 data = ${lookup{$domain}lsearch{/etc/virtual}}
2632
2633 The \(/etc/virtual)\ file contains a list of domains and the addresses to
2634 which their mail should be sent. For example:
2635
2636==> domain1: postmaster@some.where.else
2637 domain2: joe@xyz.plc
2638
2639 If the number of domains is large, using a DBM or cdb file would be more
2640 efficient. If the lookup fails to find the domain in the file, the value
2641 of the \data\ option is empty, causing the router to decline.
2642
2643
2644Q0410: How can I make Exim look in the alias NIS map instead of \(/etc/aliases)\?
2645
2646A0410: The default configuration does not use NIS (many hosts don't run it).
2647 You need to change this line in the \%system_aliases%\ router:
2648
2649==> data = ${lookup{$local_part}lsearch{/etc/aliases}}
2650
2651 Change it to
2652
2653==> data = ${lookup{$local_part}nis{mail.aliases}}
2654
2655 If you want to use \(/etc/aliases)\ as well as NIS, put this router (with
2656 a different name) before or after the default one, depending on which
2657 data source you want to take precedence.
2658
2659
2660Q0411: Why will Exim deliver a message locally to any username that is longer
2661 than 8 characters as long as the first 8 characters match one of the
2662 local usernames?
2663
2664A0411: The problem is in your operating system. Exim just calls the \^^getpwnam()^^\
2665 function to test a local part for being a local login name. It does not
2666 presume to guess the maximum length of user name for the underlying
2667 operating system. Many operating systems correctly reject names that are
2668 longer than the maximum length; yours is apparently deficient in this
2669 regard. To cope with such systems, Exim has an option called
2670 \max_user_name_length\ which you can set to the maximum allowed length.
2671
2672
2673Q0412: Why am I seeing the error \*bad mode (100664) for /home/test/.forward*\?
2674 I've looked through the documentation but can't see anything to suggest
2675 that Exim has to do anything other than read the \(.forward)\ file.
2676
2677A0412: For security, Exim checks for mode bits that shouldn't be set, by
2678 default 022. You can change this by setting the \modemask\ option of the
2679 \%redirect%\ router that is handling \(.forward)\ files.
2680
2681
2682Q0413: When a user's \(.forward)\ file is syntactially invalid, Exim defers
2683 delivery of all messages to that user, which sometimes include the
2684 user's own test messages. Can it be told to ignore the \(.forward)\ file
2685 and/or inform the user of the error?
2686
2687A0413: Setting \skip_syntax_errors\ on the redirect router causes syntax
2688 errors to be skipped. When dealing with users' \(.forward)\ files it is best
2689 to combine this with a setting of \syntax_errors_to\ in order to send
2690 a message about the error to the user. However, to avoid an infinite
2691 cascade of messages, you have to be able to send to an address that
2692 bypasses \(.forward)\ file processing. This can be done by including a
2693 router like this one
2694
2695==> real_localuser:
2696 driver = accept
2697 check_local_user
2698 transport = local_delivery
2699 prefix = real-
2700
2701 before the \%redirect%\ router that handles \(.forward)\ files. This will
2702 do an ordinary local delivery without \(.forward)\ processing, if the
2703 local part is prefixed by \"real-"\. You can then set something like
2704 the following options on the \%redirect%\ router:
2705
2706==> skip_syntax_errors
2707 syntax_errors_to = real-$local_part@$domain
2708 syntax_errors_text = "\
2709 This is an automatically generated message. An error has been \
2710 found\nin your .forward file. Details of the error are reported \
2711 below. While\nthis error persists, messages addressed to you will \
2712 get delivered into\nyour normal mailbox and you will receive a \
2713 copy of this message for\neach one."
2714
2715 A final tidying setting to go with this is a rewriting rule that changes
2716 \"real-username"\ into just \"username"\ in the headers of the message:
2717
2718==> \N^real-([^@]+)@your\.dom\.ain$\N $1@your.dom.ain h
2719
2720 This means that users won't ever see the \"real-"\ prefix, unless they
2721 look at the ::Envelope-To:: header.
2722
2723
2724Q0414: I have set \caseful_local_part\ on the routers that handle my local
2725 domain because my users have upper case letters in their login names,
2726 but incoming mail now has to use the correct case. Can I relax this
2727 somehow?
2728
2729A0414: If you really have to live with caseful user names but want incoming
2730 local parts to be caseless, then you have to maintain a file, indexed by
2731 the lower case forms, that gives the correct case for each login, like
2732 this:
2733
2734==> admin: Admin
2735 steven: Steven
2736 mcdonald: McDonald
2737 lamanch: LaManche
2738 ...
2739
2740 and at the start of the routers that handle your local domain, put one
2741 like this:
2742
2743==> set_case_router:
2744 driver = redirect
2745 data = ${lookup{${lc:$local_part}}lsearch{/the/file}}
2746 qualify_preserve_domain
2747
2748 For efficiency, you should also set the \redirect_router\ option to cause
2749 processing of the changed address to begin at the next router. If you
2750 are otherwise using the default configuration, the setting would be
2751
2752==> redirect_router = system_aliases
2753
2754 If there are lots of users, then a DBM or cdb file would be more
2755 efficient than a linear search. If you are handling several domains,
2756 you will have to extend this configuration to cope appropriately.
2757
2758
2759Q0415: Can I use my existing alias files and forward files as well as procmail
2760 and effectively drop in Exim in place of Sendmail ?
2761
2762A0415: Yes, as long as your alias and forward files don't assume that pipes are
2763 going to run under a shell. If they do, you either have to change them,
2764 or configure Exim to use a shell (which it doesn't by default).
2765
2766
2767Q0416: What is quickest way to set up Exim so any message sent to a
2768 non-existing user would bounce back with a different message, based
2769 on the name of non-existing user?
2770
2771A0416: Place this router last, so that it catches any local addresses that
2772 are not otherwise handled:
2773
2774==> non_exist:
2775 driver = accept
2776 transport = non_exist_reply
2777 no_verify
2778
2779 Then add the following transport to the transports section:
2780
2781==> non_exist_reply:
2782 driver = autoreply
2783 user = exim
2784 to = $sender_address
2785 subject = User does not exist
2786 text = You sent mail to $local_part. That's not a valid user here. \
2787 The subject was: $subject.
2788
2789 If you want to pick up a message from a file, you can use the \file\
2790 option (use \file_expand\ if you want its contents expanded).
2791
2792
2793Q0417: What do I need to do to make Exim handle \(/usr/ucb/vacation)\ processing
2794 automatically, so that people could just create a \(.vacation.msg)\ file in
2795 their home directory and not have to edit their \(.forward)\ file?
2796
2797A0417: Add a new router like this, immediately before the normal \%localuser%\
2798 router:
2799
2800==> vacation:
2801 driver = accept
2802 check_local_user
2803 require_files = $home/.vacation.msg
2804 transport = vacation_transport
2805 unseen
2806
2807 and a matching new transport like this:
2808
2809==> vacation_transport:
2810 driver = pipe
2811 command = /usr/ucb/vacation $local_part
2812
2813 However, some versions of \(/usr/ucb/vacation)\ do not work properly unless
2814 the DBM file(s) it uses are created in advance - it won't create them
2815 itself. You also need a way of removing them when the vacation is over.
2816
2817 Another possibility is to use a fixed filter file which is run whenever
2818 \(.vacation.msg)\ exists, for example:
2819
2820==> vacation:
2821 driver = redirect
2822 check_local_user
2823 require_files = $home/.vacation.msg
2824 file = /some/central/filter
2825 allow_filter
2826
2827 The filter file should use the \"if personal"\ check before sending mail,
2828 to avoid generating automatic responses to mailing lists. If sending a
2829 message is all that it does, this doesn't count as a ``significant''
2830 delivery, so the original message goes on to be delivered as normal.
2831
2832 Yet another possibility is to make use of Exim's \%autoreply%\ transport,
2833 and not use \(/usr/ucb/vacation)\ at all.
2834
2835
2836Q0418: I want to use a default entry in my alias file to handle unknown local
2837 parts, but it picks up the local parts that the aliases generate. For
2838 example, if the alias file is
2839
2840==> luke.skywalker: luke
2841 ls: luke
2842 *: postmaster
2843
2844 then messages addressed to \/luke.skywalker/\ end up at \/postmaster/\.
2845
2846A0418: The default mechanism works best with virtual domains, where the
2847 generated address is not in the same domain. If you just want to pick up
2848 all unknown local parts and send them to postmaster, an easier way to do
2849 it is to put this as your last router:
2850
2851==> unknown:
2852 driver = redirect
2853 data = postmaster
2854 no_verify
2855
2856 Another possibility is to put the redirect router for these aliases
2857 after all the other routers, so that local parts which are user names
2858 get picked off first. You will need to have two aliasing routers if
2859 there are some local parts (e.g. \/root/\) which are login names, but which
2860 you want to handle as aliases.
2861
2862
2863Q0419: I have some obsolete domains which people have been warned not to use
2864 any more. How can I arrange to delete any mail that is sent to them?
2865
2866A0419: To reject them at SMTP time, with a customized error message, place
2867 statments like this in the ACL:
2868
2869==> deny message = The domain $domain is obsolete
2870 domains = lsearch;/etc/exim/obsolete.domains
2871
2872 For messages that don't arrive over SMTP, you can use a router like
2873 this to bounce them:
2874
2875==> obsolete:
2876 driver = redirect
2877 domains = lsearch;/etc/exim/obsolete.domains
2878 allow_fail
2879 data = :fail: the domain $domain is obsolete
2880
2881 If you just want to throw away mail to those domains, accept them at
2882 SMTP time, and use a router like this:
2883
2884==> obsolete:
2885 domains = lsearch;/etc/exim/obsolete.domains
2886 data = :blackhole:
2887
2888
2889Q0420: How can I arrange that mail addressed to \(anything@something.mydomain.com)\
2890 gets delivered to \(something@mydomain.com)\?
2891
2892A0420: Set up a router like this:
2893
2894==> user_from_domain:
2895 driver = redirect
2896 data = ${if match{$domain}{\N^(.+)\.mydomain\.com$\N}\
2897 {$1@mydomain.com}}
2898
2899
2900Q0421: I can't get a regular expression to work in a \local_parts\ option on
2901 one of my routers.
2902
2903A0421: Have you remembered to protect any backslash and dollar characters in
2904 your regex from unwanted expansion? The easiest way is to use the
2905 \"@\N"\ facility, like this:
2906
2907==> local_parts = \N^0740\d{6}\N
2908
2909
2910Q0422: How can I arrange for all addresses in a group of domains \(*.example.com)\
2911 to share the same alias file? I have a number of such groups.
2912
2913A0422: For a single group you could just hard wire the file name into a router
2914 that had
2915
2916==> domains = *.example.com
2917
2918 set, to restrict it to the relevant domains. For a number of such groups
2919 you can create a file containing the domains, like this:
2920
2921==> *.example1.com example1.com
2922 *.example2.com example2.com
2923 ...
2924
2925 Then create a router like this
2926
2927==> domain_aliases:
2928 driver = redirect
2929 domains = partial-lsearch;/that/file
2930 data = ${lookup{$local_part}lsearch*{/etc/aliases.d/$domain_data}}
2931
2932 The variable \$domain_data$\ contains the data that was looked up when the
2933 \domains\ option was matched, i.e. \"example1.com"\, \"example2.com"\, etc.
2934 in this case.
2935
2936
2937Q0423: Some of our users have no home directories; the field in the password
2938 file contains \(/no/home/dir)\. This causes the error \*failed to stat
2939 /no/home/dir (No such file or directory)*\ when Exim tries to look for a
2940 \(.forward file)\, and the delivery is deferred.
2941
2942A0423: There are two issues involved here:
2943
2944 (1) With the default configuration, you are asking Exim to check for a
2945 \(.forward)\ file in the user's home directory. If no file is found,
2946 Exim tries to \^^stat()^^\ the home directory. This is so that it will
2947 notice a missing NFS home directory, and not treat it as if the
2948 \(.forward)\ file did not exist. This \^^stat()^^\ is failing when the
2949 home directory really doesn't exist. You should arrange for the
2950 \%userforward%\ router not to run for these special users, by adding
2951 this line:
2952
2953==> condition = ${if eq {$home}{/no/home/dir}{no}{yes}}
2954
2955 (2) If you use \check_local_user\ on another router to route to a local
2956 transport (again, this is what is in the default configuration), you
2957 will also have to specify a current directory for the transport, because
2958 by default it makes the home directory current. This is easily done by
2959 adding
2960
2961==> current_directory = /
2962
2963 to the transport or
2964
2965==> transport_current_directory = /
2966
2967 to the router. Or you can add \home_directory\ to the transport, because
2968 the current directory defaults to the home directory.
2969
2970
2971Q0424: How can I disable Exim's de-duplication features? I want it to do two
2972 deliveries if two different aliases expand to the same address.
2973
2974A0424: This is not possible. Duplication has other ramifications other than
2975 just (in)convenience. Consider:
2976
2977 . Message is addressed to A and to B.
2978
2979 . Both A and B are aliased to C.
2980
2981 . Without de-duplication, two deliveries to C are scheduled.
2982
2983 . One delivery happens, Exim records that it has delivered the message
2984 to C.
2985
2986 . The next delivery fails (C's mailbox is over quota, say).
2987
2988 Next time round, Exim wants to know if it has already delivered to C or
2989 not, before scheduling a new delivery. Has it? Obviously, if duplicate
2990 deliveries are supported, it has to remember not only that it has
2991 delivered to C but also the ``history'' of how that delivery happened - in
2992 effect an ancestry list back to the original envelope address. This it
2993 does not do, and changing it to work in that way would be a lot of work
2994 and a big upheaval.
2995
2996 The best way to get duplicate deliveries if you want them is not to use
2997 aliases, but to route the addresses directly to a transport, e.g.
2998
2999==> duplicates:
3000 driver = accept
3001 local_parts = lsearch;/etc/list/of/special/local/parts
3002 transport = local_delivery
3003 user = exim
3004
3005
3006Q0425: My users' mailboxes are distributed between several servers according to
3007 the first letter of the user name. All the servers receive incoming mail
3008 at random. I would like to have the same configuration file for all the
3009 servers, which does local delivery for the mailboxes it holds, and sends
3010 other addresses to the correct other server. Is this possible?
3011
3012A0425: It is easiest if you arrange for all the users to have password entries
3013 on all the servers. This means that non-existent users can be detected
3014 at the first server they reach. Set up a file containing a mapping from
3015 the first letter of the user names to the servers where their mailboxes
3016 are held. For example:
3017
3018==> a: server1
3019 b: server1
3020 c: server2
3021 ...
3022
3023 Before the normal \%localuser%\ router, place the following router:
3024
3025==> mailbox_host:
3026 driver = manualroute
3027 check_local_user
3028 transport = remote_smtp
3029 route_list = * ${lookup{${substr_0_1:$local_part}}lsearch{/etc/mapfile}}
3030 self = pass
3031
3032 This router checks for a local account, then looks up the host from the
3033 first character of the local part. If the host is not the local host,
3034 the address is routed to the \%remote_smtp%\ transport, and sent to the
3035 correct host. If the host is the local host, the \self\ option causes
3036 the router to pass the address to the next router, which does a local
3037 delivery.
3038
3039 The router is skipped for local parts that are not the names of local
3040 users, and so these addresses fail.
3041
3042
3043Q0426: One of the things I want to set up is for \(anything@onedomain)\ to forward
3044 to \(anything@anotherdomain)\. I tried adding \($local_part@anotherdomain)\ to
3045 my aliases but it did not expand - it sent it to that literal address.
3046
3047A0426: If you want to do it that way, you can use the \"expand"\ operator on
3048 the lookup used in the data option of the redirect router. For example:
3049
3050==> data = ${expand:${lookup{$local_part}lsearch*{/etc/aliases}}}
3051
3052 Another approach is to use a router like this:
3053
3054==> forwarddomain:
3055 driver = redirect
3056 domains = onedomain
3057 data = $local_part@anotherdomain
3058
3059 The value of \data\ can, of course, be more complicated, involving
3060 lookups etc. if you have lots of different cases.
3061
3062
3063Q0427: How can I have an address looked up in two different alias files, and
3064 delivered to all the addresses that are found?
3065
3066A0427: Use a router like this:
3067
3068==> multi_aliases:
3069 driver = redirect
3070 data = ${lookup{$local_part}lsearch{/etc/aliases1}\
3071 {$value${lookup{$local_part}lsearch{/etc/aliases2}{,$value}}}\
3072 {${lookup{$local_part}lsearch{/etc/aliases2}{$value}fail}}}\
3073
3074 If the first lookup succeeds, the result is its data, followed by the
3075 data from the second lookup, if any, separated by a comma. If the first
3076 lookup fails, the result is the data from the third lookup (which also
3077 looks in the second file), but if this also fails, the entire expansion
3078 is forced to fail, thereby causing the router to decline.
3079
3080 Another approach is to use two routers, with the first re-generating the
3081 original local part when it succeeds. This won't get processed by the
3082 same router again. For example:
3083
3084==> multi_aliases1:
3085 driver = redirect
3086 data = ${lookup{$local_part}lsearch{/etc/aliases1}{$value,$local_part}}
3087
3088==> multi_aliases2:
3089 data = ${lookup{$local_part}lsearch{/etc/aliases2}}
3090
3091 This scales more easily to three or more alias files.
3092
3093
3094Q0428: I've converted from Sendmail, and I notice that Exim doesn't make use
3095 of the \"owner-"\ entries in my alias file to change the sender address in
3096 outgoing messages to a mailing list.
3097
3098A0428: If you have an alias file with entries like this:
3099
3100==> somelist: a@b, c@d, ...
3101 owner-somelist: postmaster
3102
3103 Sendmail assumes that the second entry specifies a new sender address
3104 for the first. Exim does not make this assumption. However, you can make
3105 it take the same action, by adding
3106
3107==> errors_to = owner-$local_part@whatever.domain
3108
3109 to the configuration for your aliasing router. This is fail-safe,
3110 because Exim verifies a new sender address before using it. Thus, the
3111 change of sender address occurs only when the owner entry exists.
3112
3113
3114Q0429: I would like to deliver mail addressed to a given domain to local
3115 mailboxes, but also to generate messages to the envelope senders.
3116
3117A0429: You can do this with an ``unseen'' router and an \%autoreply%\ transport,
3118 along the following lines:
3119
3120==> # Router
3121 auto_warning_r:
3122 driver = accept
3123 check_local_user
3124 domains = <domains you want to do this for>
3125 condition = ${if eq{$sender_address}{}{no}{yes}}
3126 transport = warning_t
3127 no_verify
3128 unseen
3129
3130 Place this router immediately before the normal \%localuser%\ router. The
3131 \unseen\ option means that the address is still passed on to the next
3132 router. The transport is configured like this:
3133
3134==> # Transport
3135 warning_t:
3136 driver = autoreply
3137 file = /usr/local/mail/warning.txt
3138 file_expand
3139 from = postmaster@your.domain
3140 to = $sender_address
3141 user = exim
3142 subject = Re: Your mail to $local_part@$domain
3143
3144 Note the use of the \condition\ option to avoid attempting to send a
3145 message when there is no sender (that is, when the incoming message is a
3146 bounce message). You can of course extend this to include other
3147 conditions. If you want to log the sending of messages, you can add
3148
3149==> log = /some/file
3150
3151 to the transport and also make use of the \once\ option if you want to
3152 send only one message to each sender.
3153
3154
3155Q0430: Whenever Exim tries to route a local address, it gives a permission
3156 denied error for the \(.forward)\ file, like this:
3157
3158==> 1998-08-10 16:55:32 0z5y2W-0000B8-00 == xxxx@yyy.zzz <xxxx@yyy.zz>
3159 D=userforward defer (-1): failed to open /home/xxxx/.forward
3160 (userforward router): Permission denied (euid=1234 egid=101)
3161
3162A0430: Have you remembered to make Exim setuid \/root/\?
3163
3164
3165Q0431: How do I configure Exim to allow arbitrary extensions in local parts, of
3166 the form \/+extension/\?
3167
3168A0431: Add this pre-condition to the relevant router:
3169
3170==> local_part_suffix = +*
3171
3172 If you want the extensions to be optional, also add the option
3173
3174==> local_part_suffix_optional
3175
3176 When the router runs, \$local_part$\ contains the local part with the
3177 extension removed, and the extension (if any) is in \$local_part_suffix$\.
3178 If you have set \check_local_user\, the test is carried out after the
3179 extension is removed.
3180
3181
3182Q0432: I use NIS for my user data. How can I stop Exim rejecting mail when my
3183 NIS servers are being restarted?
3184
3185A0432: Exim doesn't know that you are using NIS; it just calls the \^^getpwnam()^^\
3186 function, which is routed by nsswitch. Unfortunately, \^^getpwnam()^^\
3187 was never designed to be routed through NIS, and it returns NULL if the
3188 entry is not found or if the connection to the NIS server fails. This
3189 means that Exim cannot tell the difference between ``no such user'' and
3190 ``NIS is down''.
3191
3192 Crutches to help with this problem are \finduser_retries\ in Exim, and
3193 \^nscd^\ on the Unix side, but they are not perfect, and mail can still
3194 be lost. However, Nico Erfurth pointed out that you can create a router
3195 for Exim that tests for the availability of NIS, and force a defer if
3196 NIS is not running:
3197
3198==> check_nis:
3199 driver = redirect
3200 data = ${lookup {$local_part} nis {passwd}{}}
3201
3202 This should be placed before any router that makes any use of NIS,
3203 typically at the start of your local routers. How does it work? If
3204 your NIS server is reachable, the lookup will take place, and whether it
3205 succeeds or fails, the result is an empty strting. This causes the
3206 router to decline, and the address is passed to the following routers.
3207 If your NIS server is down, the lookup defers, and this causes the
3208 router to defer. A verification of an incoming address gets a temporary
3209 rejection, and a delivery is deferred till later.
3210
3211
3212Q0433: How can I arrange for a single address to be processed by \*both*\
3213 \%redirect%\ \*and*\ \%accept%\?
3214
3215A0433: Check out the \unseen\ option.
3216
3217
3218Q0434: How can I redirect all local parts that are not in my system aliases to
3219 a single address? I tried using an asterisk in the system alias file
3220 with an \"lsearch*"\ lookup, but that send \*all*\ messages to the
3221 default address.
3222
3223A0434: If your alias file generates addresses in the local domain, they are
3224 also processed as a potential aliases. For example, suppose this is your
3225 alias file:
3226
3227==> caesar: jc
3228 anthony: ma
3229 *: brutus
3230
3231 The local part \/caesar/\ is aliased to \/jc/\, but that address is then
3232 reprocessed by the routers. As the address is in the local domain, the
3233 alias file is again consulted, and this time the default matches. In
3234 fact after the second aliasing, \/brutus/\ is also processed again from
3235 the start, and is aliased to itself. However, this happens only once,
3236 because the next time, Exim notices that the aliasing router has already
3237 processed \/brutus/\, so the router is skipped in order to avoid
3238 looping.
3239
3240 There are several ways of solving this problem; which one you use
3241 depends on your aliasing data.
3242
3243 (1) If the result of aliasing is always a local user name, that is,
3244 aliasing never generates another alias, you can use the
3245 \redirect_router\ option on the router to specify that processing
3246 the generated addresses must start at the next router. For example:
3247
3248==> redirect_router = userforward
3249
3250 assuming that the next router is called \%userforward%\. This
3251 ensures that there is at most one pass through the aliasing router.
3252
3253 (2) If you cannot rely on aliases generating non-aliases, it is often
3254 easier not to use a default alias, but instead to place a router
3255 such as the one below after all the other local routers (for the
3256 relevant domains):
3257
3258==> catch_unknown:
3259 driver = redirect
3260 domains = ...
3261 data = brutus@$domain
3262
3263 Note that the default aliasing technique works more successfully for
3264 virtual domains (see Q0401) because the generated address for the
3265 default is not usually in the same virtual domain as the incoming
3266 address.
3267
3268
3269Q0435: My alias file contains fully qualified addresses as keys, and some
3270 wildcard domains in the form @foo.bar. Can Exim handle these?
3271
3272A0435: You can handle fully qualified addresses with this router:
3273
3274==> qualified_aliases:
3275 driver = redirect
3276 data = ${lookup{$local_part@$domain}lsearch{/etc/aliases}}
3277
3278 (Add any other options you need for the \%redirect%\ router.) Place this
3279 router either before or after the default aliases router that looks up
3280 the local part only. (Or, if you have no unqualified aliases, replace
3281 the default router.)
3282
3283 To handle wildcards in the form @foo.bar you will need yet another
3284 router. (Wildcards of the form *@foo.bar can be handled by an lsearch*@
3285 lookup.) Something like this:
3286
3287==> wildcard_aliases:
3288 driver = redirect
3289 data = ${lookup{@$domain}lsearch{/etc/aliases}}
3290
3291 Place this after the routers that handle the more specific aliases.
3292
3293
3294
32955. FILTERING
3296
3297Q0501: My filter isn't working. How can I test it?
3298
3299A0501: Use the \-bf-\ option (\-bF-\ for a system filter) to test the basic operation
3300 of your filter. You can request debugging information for filtering only
3301 by adding \"-d-all+filter"\ to the command.
3302
3303
3304Q0502: What I really need is the ability to obtain the result of a pipe
3305 command so that I can filter externally and redirect internally. Is
3306 this possible?
3307
3308A0502: The result of a pipe command is not available to a filter, because Exim
3309 does not run any actual deliveries while filtering. It just sets up
3310 deliveries at this time. They all actually happen later. If you want to
3311 run pipes and examine their results, you need to set up a single
3312 delivery to a delivery agent such as \^procmail^\ which provides this kind
3313 of facility.
3314
3315 An possible alternative is to use the \"${run"\ expansion item to run an
3316 external command while filtering. In this case, you can make use of some
3317 of the results of the command.
3318
3319
3320Q0503: I received a message with a ::Subject:: line that contained a non-printing
3321 character (a carriage return). This messed up my filter file. Is there a
3322 way to get round it?
3323
3324A0503: Instead of \"$h_subject:"\ use \"${escape:$h_subject:}"\
3325
3326
3327Q0504: I want to search for \"$"\ in the subject line, but I can't seem to get
3328 the syntax.
3329
3330A0504: Try one of these:
3331
3332==> if $h_subject: contains \$ then ...
3333 if $h_subject: contains "\\$" then ...
3334
3335
3336Q0505: My problem is that Exim replaces \$local_part$\ with an empty string in the
3337 system filtering. What's wrong or what did I miss?
3338
3339A0505: A message may have many recipients. The system filter is run just once
3340 at the start of a delivery attempt. Consequently, it does not make sense
3341 to set \$local_part$\. Which recipient should it be set to? However, you
3342 can access all the recipients from a system filter via the variable
3343 called \$recipients$\.
3344
3345
3346Q0506: Using \$recipients$\ in a system filter gives me another problem: how can
3347 I do a string lookup if \$recipients$\ is a list of addresses?
3348
3349A0506: Check out the section of the filter specification called \*Testing a list of
3350 addresses*\. If that doesn't help, you may have to resort to calling an
3351 embedded Perl interpreter - but that is expensive.
3352
3353
3354Q0507: What are the main differences between using an Exim filter and using
3355 \^procmail^\?
3356
3357A0507: Exim filters and \^procmail^\ provide different facilities. Exim filters run
3358 at routing time, before any deliveries are done. A filter is like a
3359 ``\(.forward)\ file with conditions''. One of the benefits is de-duplication.
3360 Another is that if you forward, you are forwarding the original message.
3361
3362 However, this does mean that pipes etc. are not run at filtering time,
3363 nor can you change the headers, because the message may have other
3364 recipients and Exim keeps only a single set of headers.
3365
3366 \^procmail^\ runs at delivery time. This is for one recipient only, and so
3367 it can change headers, run pipes and check the results, etc. However, if
3368 it wants to forward, it has to create a new message containing a copy
3369 of the original message.
3370
3371 It's your choice as to which of these you use. You can of course use
3372 both.
3373
3374
3375Q0508: How can I allow the use of relative paths in users' filter files when
3376 the directories concerned are not available from the password data?
3377
3378A0508: You need to be running Exim 4.11 or later. You can then specify a value
3379 for \$home$\ by setting the router_home_directory option on the
3380 \%redirect%\ router.
3381
3382 For earlier releases, there is no way to specify the value of \$home$\
3383 for a \%redirect%\ router; it either comes from the password data as a
3384 result of \check_local_user\, or is unset.
3385
3386
3387Q0509: How can I set up a filter file to detect and block virus attachments?
3388
3389A0509: Exim's filter facilities aren't powerful enough to do much more than
3390 very crude testing. Most people that want virus checking are nowadays
3391 using one of the separate scanning programs such as \^exiscan^\ (see
3392 \?http://duncanthrax.net/exiscan/?\). There is some further information
3393 about scanning with Exim via \?http://www.timj.co.uk/linux/exim.php?\.
3394
3395
3396Q0510: Is it possible to write code for scanning messages in Python?
3397
3398A0510: \^elspy^\ is a layer of glue code that enables you to write Python code
3399 to scan email messages at SMTP time. \^elspy^\ also includes a small
3400 Python library with common mail-scanning tools, including an interface
3401 to SpamAssassin and a simple but effective virus detector. You can
3402 optain \^elspy^\ from \?http://elspy.sourceforge.net/?\.
3403
3404
3405Q0511: Whenever my system filter uses a \mail\ command to send a message, I get
3406 the error \*User 0 set for address_reply transport is on the never_users
3407 list*\. What does this mean?
3408
3409A0511: The system filter runs as \/root/\ in Exim 4, unless you set
3410 \system_filter_user\ to specify otherwise. When you set up a delivery
3411 direct from a system filter (an autoreply is a special kind of
3412 ``delivery'') the transport runs as the same user, unless it has a
3413 \user\ setting of its own. Normally, deliveries are not allowed to run
3414 as \/root/\ as a security precaution; this is implemented by the
3415 \never_users\ option.
3416
3417 The easiest solution is to add this to your configuration:
3418
3419==> system_filter_user = exim
3420
3421 The system filter then runs as \/exim/\ instead of \/root/\.
3422 Alternatively, you can arrange for autoreplies from the system filter to
3423 use a special transport of their own, and set the \user\ option on that
3424 transport.
3425
3426
3427Q0512: I'm trying to reference the ::Envelope-To:: header in my filter, but
3428 \$h_envelope-to:$\ is always empty.
3429
3430A0512: ::Envelope-To:: is added at delivery time, by the transport. Therefore,
3431 the header doesn't exist at filter time. In a user filter, the values
3432 you probably want are in \$original_local_part$\ and
3433 \$original_domain$\. In a system filter, the complete list of all
3434 envelope recipients is in \$recipients$\.
3435
3436
3437Q0513: I want my system filter to freeze all mails greater than 500K in size,
3438 but to exclude those to a specific domain. However, I don't seem to be
3439 able to use \$domain$\ in a system filter.
3440
3441A0513: You cannot do this in a system filter, because a single message may have
3442 multiple recipients, some in the special domain, and some not. That is
3443 also the reason why \$domain$\ is not set in a system filter.
3444
3445 If you want to take actions on a per-recipient basis, you have to do it
3446 in a router. However, freezing is not appropriate, because freezing
3447 stops all deliveries. You could, however, delay delivery to all but the
3448 special domains by using something like this:
3449
3450==> delay_if_too_big:
3451 driver = redirect
3452 domains = !the.special.domain
3453 condition = ${if >{$message_size}{500K}{yes}{no}}
3454 allow_defer
3455 data = :defer: message too big.
3456
3457 However, there isn't an easy way of ``releasing'' such messages at
3458 present.
3459
3460
3461Q0514: When I try to send to two addresses I get an error in the filter
3462 file \*malformed address: , e@fgh.com may not follow a@bcd.com*\. What
3463 is going on?
3464
3465A0514: Have you got
3466
3467==> deliver "a@bcd.com, e@fgh.com"
3468
3469 in your filter? If so, that is your problem. You should have
3470
3471==> deliver a@bcd.com
3472 deliver e@fgh.com
3473
3474 Each \deliver\ command expects just one address.
3475
3476
3477
34786. DELIVERY
3479
3480Q0601: What does the error \*Neither the xxx router nor the yyy transport set
3481 a uid for local delivery of...*\ mean?
3482
3483A0601: Whenever Exim does a local delivery, it runs a process under a specific
3484 user and group id (uid and gid). For deliveries into mailboxes, and to
3485 pipes and files set up by forwarding, it normally picks up the uid/gid
3486 of the receiving user. However, if an address is directed to a pipe or a
3487 file by some other means, such an entry in the system alias file of the
3488 form
3489
3490==> majordomo: |/local/mail/majordomo ...
3491
3492 then Exim has to be told what uid/gid to use for the delivery. This can
3493 be done either on the routerr that handles the address, or on the
3494 transport that actually does the delivery. If a pipe is going to run a
3495 setuid program, then it doesn't matter what uid Exim starts it out with,
3496 and so the most straightforward thing is to put
3497
3498==> user = exim
3499
3500 on either the router or the transport. A setting on the transport
3501 overrides a setting on the router, so if the same transport is being
3502 used with several routers, you should set the user on it only if you
3503 want the same uid to be used in all cases.
3504
3505 In the default configuration, the transports used for file and pipe
3506 deliveries are the ones called \address_file\ and \address_pipe\. You
3507 can specify different transports by setting, for example,
3508
3509==> pipe_transport = special_pipe_transport
3510
3511 on the \%system_aliases%\ router. Then you can set up \%special_pipe_transport%\
3512
3513==> special_pipe_transport:
3514 driver = pipe
3515 user = ????
3516
3517 which will be used only for pipe deliveries from that one router.
3518 What you put for the ???? is up to you, and depends on the particular
3519 circumstances.
3520
3521
3522Q0602: Exim keeps crashing with segmentation errors (signal 11 or 139) during
3523 delivery. This seems to happen when it is about to contact a remote
3524 host or when a delivery is deferred.
3525
3526A0602: This could be a problem with Exim's databases. Try running a delivery
3527 with debugging turned on. If the last line of the debug output is
3528 something like this:
3529
3530==> locked /var/spool/exim/db/retry.lockfile
3531
3532 the crash is happening inside the DBM library. Check that your DBM
3533 library is correctly installed. In particular, if you have installed a
3534 second DBM library onto a system that already had one, check that its
3535 version of \(ndbm.h)\ is being seen first. For example, if the new
3536 version is in \(/usr/local/include)\, check that there isn't another
3537 version in \(/usr/include)\. If you are using Berkeley db, you can set
3538
3539==> USE_DB=yes
3540
3541 in your \(Local/Makefile)\ to avoid using \(ndbm.h)\ altogether. This is
3542 particularly relevant for version 2 (or later) of Berkeley db, because
3543 no \(ndbm.h)\ file is distributed with it. Another thing you can try is
3544 to run
3545
3546==> exim_dumpdb /var/spool/exim retry
3547
3548 to see if it also crashes, or build the \^test_dbfn^\ tool and fiddle
3549 around with it. If both fail, it is most almost certainly a problem with
3550 your DBM library. You could try to update it, or force Exim to use
3551 another library. See the file \(doc/dbm.discuss.txt)\ for hints about
3552 this.
3553
3554
3555Q0603: How can mails that are being routed through routers that do not set
3556 \check_local_user\ be delivered under the uid of the recipient?
3557
3558A0603: Q0601 contains background information on this. If you are using, say, an
3559 alias file to direct messages to specific mailboxes, you can use
3560 the \user\ option on either the router or the transport to set the uid.
3561 What you put in the setting depends on how the required uid is to be
3562 found. It could be looked up in a file or computed somehow from the
3563 local part, for example.
3564
3565
3566Q0604: I want to use MMDF-style mailboxes. How can I get Exim to append the
3567 ctrl-A characters that separate indvidual emails?
3568
3569A0604: Set the \message_suffix\ option in the \%appendfile%\ transport. In fact,
3570 for MMDF mailboxes you need a prefix as well as a suffix to get it
3571 working right, so your transport should contain these settings:
3572
3573==> message_prefix = "\1\1\1\1\n"
3574 message_suffix = "\1\1\1\1\n"
3575
3576 Also, you need to change the \check_string\ and \escape_string\ settings so
3577 that the escaping happens for lines in the message that happen to begin
3578 with the MMDF prefix or suffix string, rather than ``From'' (the default):
3579
3580==> check_string = "\1\1\1\1\n"
3581 escape_string = "\1\1\1\1 \n"
3582
3583 Adding a space to the line is sufficient to prevent it being taken as a
3584 separator.
3585
3586
3587Q0605: If a user's mailbox is over quota, is there a way for me to set it up so
3588 that the mail bounces to the sender and is not stored in the mail queue?
3589
3590A0605: In the retry section of the configuration, put
3591
3592==> *@your.dom.ain quota
3593
3594 That is, provide no retry timings for over quota errors. They will then
3595 bounce immediately. Alternatively, you can set up retries for a short
3596 time only, or use something like this:
3597
3598==> *@your.dom.ain quota_7d
3599 *@your.dom.ain quota F,2h,15m; F,3d,1h
3600
3601 which bounces immediately if the user's mailbox hasn't been read for 7
3602 days, but otherwise tries for up to 3 days after the first quota
3603 failure.
3604
3605
3606Q0606: I'm using tmail to do local deliveries, but when I turned on the
3607 \use_crlf\ option on the \%pipe%\ transport (tmail prefers \"@\r@\n"\
3608 terminations) message bodies started to vanish.
3609
3610A0606: You need to unset the \mesage_prefix\ option, or change it so that its
3611 default \"@\n"\ terminator becomes \"@\r@\n"\. For example, the
3612 transport could be:
3613
3614==> local_delivery_mbx:
3615 driver = pipe
3616 command = /usr/local/bin/tmail $local_part
3617 user = exim
3618 current_directory = /
3619 use_crlf
3620 message_prefix =
3621
3622 The reason for this is as follows: tmail uses the line terminator on
3623 the first line it sees to determine whether lines are terminated by
3624 \"@\r@\n"\ or \"@\n"\. If the latter, it moans to stderr and changes subsequent
3625 \"@\n"\ terminators to \"@\r@\n"\. The default setting of the \message_prefix\
3626 option is \"From ...@\n"\, and this is unaffected by the \use_crlf\ option.
3627 If you don't change this, tmail sees the first line terminated by
3628 \"@\n"\ and prepends \"@\r"\ to the \"@\n"\ terminator on all subsequent
3629 lines. However, if \use_crlf\ is set, Exim makes all other lines
3630 \"@\r@\n"\ terminated, leading to doubled \"@\r@\r@\n"\ lines and
3631 corrupt mbx mailboxes.
3632
3633
3634Q0607: When I activate ``return receipt'' for example in Netscape Mailbox
3635 sending options, then I get an error message from Exim... something
3636 like \*not supported*\. Can I activate delivery confirmations?
3637
3638A0607: Exim does not support any kind of delivery notification.
3639
3640 (1) You can configure it to recognize headers such as
3641 \Return-receipt-to:\ if you wish.
3642
3643 (2) Some people want MSN (message status notification). Such services
3644 are implemented in MUAs, and don't impact on the MTA at all.
3645
3646 (3) I investigated the RFCs which describe the DSN (delivery status
3647 notification) system. However, I was unable to specify any sensible way
3648 of actually doing anything with the data. There were comments on the
3649 mailing list at the time; many people, including me, conclude that DSN
3650 is in practice unworkable. The killer problem is with forwarding and
3651 aliasing. Do you propagate the DSN data with the generated addresses?
3652 Do you send back a ``reached end of the DSN world'' or ``expanded'' message?
3653 Do you do this differently for different kinds of aliasing/forwarding?
3654 For a user who has a \(.forward)\ file with a single address in, this
3655 might seem easy - just propagate the data. But what if there are several
3656 forwardings? If you propagate the DSN data, the sender may get back
3657 several DSN messages - and should the sender really know about the
3658 detail of the receiver's forwarding arrangements? There isn't really
3659 any way to distinguish between a \(.forward)\ file that is forwarding
3660 and one that is a mini mailing list. And so on, and so on. There are so
3661 many questions that don't have obvious answers.
3662
3663
3664Q0608: What does the message \*retry time not reached [for any host]*\ on the log
3665 mean? Why won't Exim try to deliver the message?
3666
3667A0608: That is not an error. It means exactly what it says. A previous attempt
3668 to deliver to that address failed with a temporary error, and Exim
3669 computed the earliest time at which to try again. This can apply to
3670 local as well as to remote deliveries. For remote deliveries, each host
3671 (if there are several) has its own retry time.
3672
3673 If you are running on a dial-up host, the rest of this answer probably
3674 does not apply to you. Go and read Q1404 instead. If your host is
3675 permanently online, read on...
3676
3677 Some MTAs have a retrying schedule for each message. Exim does not work
3678 like this. Retry timing is normally host-based for remote deliveries and
3679 address-based for local deliveries. (There are some exceptions for certain
3680 kinds of remote failure - see \*Errors in outgoing SMTP*\ in the manual.)
3681
3682 If a new message arrives for a failing address and the retry time has
3683 not yet arrived, Exim will log \*retry time not reached*\ and leave the
3684 message on the queue, without attempting delivery. Similarly, if a queue
3685 runner notices the message before the time to retry has arrived, it
3686 writes the same log entry. When the retry time has past, Exim attempts
3687 delivery at the next queue run. If you want to know when that will be,
3688 run the exinext utility on the address, for example:
3689
3690==> exinext user@some.domain
3691
3692 You can suppress these messages on the log by including \"-retry_defer"\
3693 in the setting of \log_selector\. You can force a delivery attempt on a
3694 specific message (overriding the retry time) by means of the -M option:
3695
3696==> exim -M 10hCET-0000Bf-00
3697
3698 If you want to do this for the entire queue, use the \-qf-\ option.
3699
3700
3701Q0609: Exim seems to be sending the same message twice, according to the log,
3702 although there is a difference in capitalization of the local part of
3703 the address.
3704
3705A0609: That is correct. The RFCs are explicit in stating that capitalization
3706 matters for local parts. For remote domains, Exim is not entitled to
3707 assume case independence of local parts. I know, it is utterly silly,
3708 and it causes a lot of grief, but that's what the rules say. Here is a
3709 quote from RFC 2821:
3710
3711 ... a command verb, an argument value other than a mailbox local-part,
3712 and free form text MAY be encoded in upper case, lower case, or any
3713 mixture of upper and lower case with no impact on its meaning. This
3714 is NOT true of a mailbox local-part. The local-part of a mailbox
3715 MUST BE treated as case sensitive. Therefore, SMTP implementations
3716 MUST take care to preserve the case of mailbox local-parts. Mailbox
3717 domains are not case sensitive. In particular, for some hosts the
3718 user "smith" is different from the user "Smith". However, exploiting
3719 the case sensitivity of mailbox local-parts impedes interoperability
3720 and is discouraged.
3721
3722
3723Q0610: How can I force the next retry time for a host to be now?
3724
3725A0610: You can change the retry time with the \^exim_fixdb^\ utility, but its
3726 interface is very clumsy. If you have a message for the host on the
3727 queue, the simplest thing to do is to force a delivery with the \-M-\
3728 command line option. If delivery succeeds, the retry data will get
3729 cleared. If the host is past the cutoff time, so that messages are
3730 bouncing immediately without trying a delivery, you can use \-odq-\ to
3731 put a message on the queue without a delivery attempt, and then use
3732 \-M-\ on it.
3733
3734
3735Q0611: I set up \"|/bin/grep Subject|/usr/bin/smbclient -M <netbiosname>"\ as an
3736 alias but it doesn't work.
3737
3738A0611: That is a shell command line. Exim does not run pipe commands under a
3739 shell by default (for added security - and it saves a process). You
3740 need something like
3741
3742==> "|/bin/sh -c '/bin/grep Subject|/usr/bin/smbclient -M <netbiosname>'"
3743
3744
3745Q0612: Why does the \%pipe%\ transport add a line starting with \">From"\ to
3746 messages?
3747
3748A0612: Actually, it adds a line starting with \"From"\ followed by a space.
3749 This is commonly referred to as the \"From_"\ line, to emphasize the
3750 fact that \"From"\ is followed by a space and not a colon. This is a
3751 pseudo-header line that contains the envelope sender address and the
3752 time of delivery. It originated as a separator line in Berkeley format
3753 mailboxes, but is also used in other contexts. (And yes, it is often
3754 confused with the ::From:: header line, and this causes a lot of grief.
3755 The use of \"From_"\ was one of the really bad email design decisions.)
3756
3757 Exim's \%pipe%\ transport adds this pseudo-header line by default
3758 because \(/usr/ucb/vacation)\ needs it, and that is one of the the most
3759 common uses of piping. The \^procmail^\ local delivery agent also makes
3760 use of the \"From_"\ line. If you do not want it, change the setting of
3761 \message_prefix\ on the \%pipe%\ transport. For example, to remove the
3762 line altogether, use
3763
3764==> message_prefix =
3765
3766 If you are not piping to \(/usr/ucb/vacation)\ or \^procmail^\, it is
3767 likely that you do not need a \"From_"\ line, and indeed it may cause
3768 problems if it is present.
3769
3770 One user reported that this line gave trouble when a pipe was used to
3771 send messages to Courier's \^deliverquota^\ program. The line was
3772 retained with the message, and caused problems for MS Exchange 2000 when
3773 retrieving messages with its built-in POP collector. Specifically, it
3774 caused Exchange to not be able to recognise message attachments.
3775
3776
3777Q0613: I have set \fallback_hosts\ on my \%smtp%\ transport, but after the error
3778 \*sem@chat.ru cannot be resolved at this time*\ Exim isn't using them.
3779
3780A0613: \fallback_hosts\ works only if an attempt at delivery to the original
3781 host(s) fails. In this case, Exim couldn't even resolve the domain
3782 \(chat.ru)\ to discover what the original hosts were, so it never got as far
3783 as the transport. However, see Q0315 for a possible solution.
3784
3785
3786Q0614: After the holidays my ISP has always hundreds of e-mails waiting for me.
3787 These are forced down Exim's throat in one go. Exim spawns a lot of
3788 kids, but is there some limit to the number of processes it creates?
3789
3790A0614: Unless you have changed \smtp_accept_queue_per_connection\ it should
3791 spawn only that many processes per connection (default 10). Your ISP
3792 may be making many connections, of course. That is limited by
3793 \smtp_accept_max\.
3794
3795
3796Q0615: When a message in the queue got to 12h old, Exim wrote \*retry timeout
3797 exceeded*\ and removed all messages in the queue to this host - even
3798 recent messages. How I can avoid this behaviour? I only want to remove
3799 messages that have exceeded the maximum retry time.
3800
3801A0615: Exim's retrying is host-based rather than message-based. The philosophy
3802 is that if a host has been down for a very long time, there is no point
3803 in keeping messages hanging around. However, you might like to check
3804 out \delay_after_cutoff\ in the \%smtp%\ transport. It doesn't do what you
3805 want, but it might help.
3806
3807
3808Q0616: Can Exim add a ::Content-Length:: header to messages it delivers?
3809
3810A0616: You could include something like
3811
3812==> headers_remove = "content-length"
3813 headers_add = "Content-Length: $message_body_size"
3814
3815 to the \%appendfile%\ transport. However, the use of ::Content-Length:: can
3816 cause several problems, and is not recommended unless you really know
3817 what you are doing. There is a discussion of the problems in
3818 \?http://home.netscape.com/eng/mozilla/2.0/relnotes/demo/content-length.html?\.
3819
3820
3821Q0617: Exim seems to be trying to deliver a message every 10 minutes, though
3822 the retry rules specify longer times after a while, because it is
3823 writing a log entry every time, like this:
3824
3825==> 1999-08-26 14:51:19 11IVsE-000MuP-00 == example@example.com T=smtp defer
3826 (-34): some host address lookups failed and retry time not reached for
3827 other hosts or connection limit reached
3828
3829A0617: It is looking at the message every 10 minutes, but it isn't actually
3830 trying to deliver. It's looking up \(example.com)\ in the DNS and finding
3831 this information:
3832
3833==> example.com. MX 10 example-com.isp.example.com.
3834 example.com. MX 0 mail.example.com.
3835 mail.example.com. A 202.77.183.45
3836 A lookup for example-com.isp.example.com. yielded NXDOMAIN
3837
3838 The last line means that there is no address (A) record in the DNS for
3839 \(example-com.isp.example.com)\. That accounts for \*some host address
3840 lookups failed*\, but the retry time for \(mail.example.com)\ hasn't been
3841 reached, which accounts for \*retry time not reached for other hosts*\.
3842
3843
3844Q0618: I am trying to set exim up to have a automatic failover if it sees that
3845 the system that it is sending all mail to is down.
3846
3847A0618: Add to the \%remote_smtp%\ transport the following:
3848
3849==> fallback_hosts = failover.server.name(s)
3850
3851 If there are several names, they must be separated by colons.
3852
3853
3854Q0619: I can't get Exim to deliver over NFS. I get the error \*fcntl() failed:
3855 No locks available*\, though the lock daemon is running on the NFS server
3856 and other hosts are able to access it.
3857
3858A0619: Check that you have \(lockd)\ running on the NFS client. This is not
3859 always running by default on some systems (Red Hat is believed to be one
3860 such system).
3861
3862
3863Q0620: Why does Exim bounce messages without even attempting delivery, giving
3864 the error \*retry time not reached for any host after a long failure
3865 period*\?
3866
3867A0620: This message means that all hosts to which the message could be sent
3868 have been failing for so long that the end of the retry period
3869 (typically 4 or 5 days) has been reached. In this situation, Exim still
3870 computes a next time to retry, but any messages that arrive in the
3871 meantime are bounced straight away. You can alter this behaviour by
3872 unsetting the \delay_after_cutoff\ option on the smtp transport. Then Exim
3873 will try most messages for those hosts once before giving up.
3874
3875
3876Q0621: My \(.forward)\ file is \"|/usr/bin/procmail -f-"\ and mail gets delivered,
3877 but there was a bounce to the sender, sending him the output of procmail.
3878 How can I prevent this?
3879
3880A0621: Exim's default configuration is set up like this:
3881
3882==> address_pipe:
3883 driver = pipe
3884 return_output
3885
3886 The \return_output\ option requests that any output that the pipe
3887 produces be returned to the sender. That is the safest default. If you
3888 don't want this, you can either remove the option altogether, or change
3889 it to \return_fail_output\, to return output only if the command fails.
3890 Note that this will affect all pipes that users run, not just your
3891 procmail one. It might be better to arrange for procmail not to produce
3892 any output when it succeeds.
3893
3894
3895Q0622: Can I write an ordinary file when I run a perl script as a transport
3896 filter for the \%remote_smtp%\ and \%address_pipe%\ transports?
3897
3898A0622: Yes, provided the file is writeable by the uid under which the transport
3899 runs (the Exim user in the case of the remote transport). However, if two
3900 messages are being delivered at once, their data will get mixed up in
3901 the file unless you implement your own locking scheme. If all you want
3902 to do is to take a copy of the message, another approach that avoids
3903 the locking problem is to use a system filter to set up an ``unseen''
3904 delivery to a file. If you only want the message's headers, you can
3905 set \message_filter_file_transport\ to point to a special \%appendfile%\
3906 transport that has \headers_only\ set.
3907
3908
3909Q0623: My \(/var/spool/mail)\ has grown drastically. Is there any possibility of
3910 using two directories?
3911
3912A0623: You can use an expansion string to split mailboxes between two
3913 directories. For example,
3914
3915==> file = /var/spool/mail${nhash_2:$local_part}/$local_part
3916
3917 which does a hash on the local part, producing either 0 or 1, thereby
3918 using \(mail0) or \(mail1)\. But remember, the MUAs that read these mailboxes
3919 also have to know where they are.
3920
3921
3922Q0624: Sendmail has a program called \^smrsh^\ that restricts what binaries
3923 can be run from sendmail aliases. Is there something like this in Exim ?
3924
3925A0624: Check out the \allow_commands\ option in the \%pipe%\ transport.
3926
3927
3928Q0625: I wish to have large emails go out one at a time.
3929
3930A0625: One possibility is to set up a router that defers all large messages,
3931 except in queue runs. Since queue runners deliver just one
3932 message at a time, if you limited the number of simultaneous queue
3933 runners to 1, you would get the effect you wanted. A suitable router
3934 might be
3935
3936==> defer_if_large_unless_queue_run:
3937 driver = redirect
3938 condition = ${if or{{queue_running}{<{$message_size}{200K}}}{no}{yes}}
3939 allow_defer
3940 data = :defer: too large for immediate delivery
3941 no_verify
3942
3943 Of course, this would always delay any large message until the next
3944 queue runner, but if you run them fairly regularly, this shouldn't be a
3945 huge problem, and may even be desirable. Note the use of \no_verify\ to
3946 ensure that this router is not used when Exim is verifying addresses.
3947
3948
3949Q0626: Exim can route local parts independent of their case, but the Cyrus LMTP
3950 daemon requires the correct case. How can I fix this?
3951
3952A0626: You need to rewrite the local part to the correct case before running
3953 the router that routes to Cyrus. For example, if you require all lower
3954 case, and your router is called \local_user\, put this router in front
3955 of it:
3956
3957==> lowercase_local:
3958 driver = redirect
3959 redirect_router = local_user
3960 domains = +local_domains
3961 data = ${lc:$local_part}@$domain
3962
3963 The setting of \redirect_router\ causes processing of the rewritten
3964 address to start at the next router, instead of the first router. See
3965 also Q0630, and C045 for a more complete Cyrus configuration.
3966
3967
3968Q0627: Is there a command I can send to Exim to retry all queued messages
3969 regardless of their retry schedule?
3970
3971A0627: The \-qff-\ option starts a queue runner that forces a delivery attempt
3972 for all messages, including frozen ones. If you use \-qf-\, frozen
3973 messages are skipped.
3974
3975
3976Q0628: I have the default retry rule, which I thought meant that Exim should
3977 keep trying for four days, but it seems to be bouncing some messages
3978 immediately.
3979
3980A0628: See Q0615 and Q0620.
3981
3982
3983Q0629: I'm having trouble with quotas and Courier, because Exim is not handling
3984 maildirsize files.
3985
3986A0629: You will do better to move the quota handling to Courier. Use \^maildrop^\
3987 as your MDA rather than direct Exim delivery. This also has the
3988 advantage that if you give web access to the mail spool (over \^sqwebmail^\)
3989 you can then use the web front end to edit \^maildrop^\ filter files.
3990
3991
3992Q0630: How can I configure Exim to deliver to a Cyrus message store?
3993
3994A0630: (1) The reference manual contains an example that uses pipe delivery.
3995
3996 (2) Here is a transport that uses LMTP delivery, assuming that
3997 \$local_part$\ contains the username: