Merge branch 'debian'
[hcoop/debian/exim4.git] / src / configure.default
1 ######################################################################
2 # Runtime configuration file for Exim #
3 ######################################################################
4
5
6 # This is a default configuration file which will operate correctly in
7 # uncomplicated installations. Please see the manual for a complete list
8 # of all the runtime configuration options that can be included in a
9 # configuration file. There are many more than are mentioned here. The
10 # manual is in the file doc/spec.txt in the Exim distribution as a plain
11 # ASCII file. Other formats (PostScript, Texinfo, HTML, PDF) are available
12 # from the Exim ftp sites. The manual is also online at the Exim website.
13
14
15 # This file is divided into several parts, all but the first of which are
16 # headed by a line starting with the word "begin". Only those parts that
17 # are required need to be present. Blank lines, and lines starting with #
18 # are ignored.
19
20
21 ########### IMPORTANT ########## IMPORTANT ########### IMPORTANT ###########
22 # #
23 # Whenever you change Exim's configuration file, you *must* remember to #
24 # HUP the Exim daemon, because it will not pick up the new configuration #
25 # until you do. However, any other Exim processes that are started, for #
26 # example, a process started by an MUA in order to send a message, will #
27 # see the new configuration as soon as it is in place. #
28 # #
29 # You do not need to HUP the daemon for changes in auxiliary files that #
30 # are referenced from this file. They are read every time they are used. #
31 # #
32 # It is usually a good idea to test a new configuration for syntactic #
33 # correctness before installing it (for example, by running the command #
34 # "exim -C /config/file.new -bV"). #
35 # #
36 ########### IMPORTANT ########## IMPORTANT ########### IMPORTANT ###########
37
38
39
40 ######################################################################
41 # MACROS #
42 ######################################################################
43 #
44
45 # If you want to use a smarthost instead of sending directly to recipient
46 # domains, uncomment this macro definition and set a real hostname.
47 # An appropriately privileged user can then redirect email on the command-line
48 # in emergencies, via -D.
49 #
50 # ROUTER_SMARTHOST=MAIL.HOSTNAME.FOR.CENTRAL.SERVER.EXAMPLE
51
52 ######################################################################
53 # MAIN CONFIGURATION SETTINGS #
54 ######################################################################
55 #
56
57 # Specify your host's canonical name here. This should normally be the fully
58 # qualified "official" name of your host. If this option is not set, the
59 # uname() function is called to obtain the name. In many cases this does
60 # the right thing and you need not set anything explicitly.
61
62 # primary_hostname =
63
64
65 # The next three settings create two lists of domains and one list of hosts.
66 # These lists are referred to later in this configuration using the syntax
67 # +local_domains, +relay_to_domains, and +relay_from_hosts, respectively. They
68 # are all colon-separated lists:
69
70 domainlist local_domains = @
71 domainlist relay_to_domains =
72 hostlist relay_from_hosts = localhost
73 # (We rely upon hostname resolution working for localhost, because the default
74 # uncommented configuration needs to work in IPv4-only environments.)
75
76 # Most straightforward access control requirements can be obtained by
77 # appropriate settings of the above options. In more complicated situations,
78 # you may need to modify the Access Control Lists (ACLs) which appear later in
79 # this file.
80
81 # The first setting specifies your local domains, for example:
82 #
83 # domainlist local_domains = my.first.domain : my.second.domain
84 #
85 # You can use "@" to mean "the name of the local host", as in the default
86 # setting above. This is the name that is specified by primary_hostname,
87 # as specified above (or defaulted). If you do not want to do any local
88 # deliveries, remove the "@" from the setting above. If you want to accept mail
89 # addressed to your host's literal IP address, for example, mail addressed to
90 # "user@[192.168.23.44]", you can add "@[]" as an item in the local domains
91 # list. You also need to uncomment "allow_domain_literals" below. This is not
92 # recommended for today's Internet.
93
94 # The second setting specifies domains for which your host is an incoming relay.
95 # If you are not doing any relaying, you should leave the list empty. However,
96 # if your host is an MX backup or gateway of some kind for some domains, you
97 # must set relay_to_domains to match those domains. For example:
98 #
99 # domainlist relay_to_domains = *.myco.com : my.friend.org
100 #
101 # This will allow any host to relay through your host to those domains.
102 # See the section of the manual entitled "Control of relaying" for more
103 # information.
104
105 # The third setting specifies hosts that can use your host as an outgoing relay
106 # to any other host on the Internet. Such a setting commonly refers to a
107 # complete local network as well as the localhost. For example:
108 #
109 # hostlist relay_from_hosts = <; 127.0.0.1 ; ::1 ; 192.168.0.0/16
110 #
111 # The "/16" is a bit mask (CIDR notation), not a number of hosts. Note that you
112 # have to include 127.0.0.1 if you want to allow processes on your host to send
113 # SMTP mail by using the loopback address. A number of MUAs use this method of
114 # sending mail. Often, connections are made to "localhost", which might be ::1
115 # on IPv6-enabled hosts. Do not forget CIDR for your IPv6 networks.
116
117 # All three of these lists may contain many different kinds of item, including
118 # wildcarded names, regular expressions, and file lookups. See the reference
119 # manual for details. The lists above are used in the access control lists for
120 # checking incoming messages. The names of these ACLs are defined here:
121
122 acl_smtp_rcpt = acl_check_rcpt
123 .ifdef _HAVE_PRDR
124 acl_smtp_data_prdr = acl_check_prdr
125 .endif
126 acl_smtp_data = acl_check_data
127
128 # You should not change those settings until you understand how ACLs work.
129
130
131 # If you are running a version of Exim that was compiled with the content-
132 # scanning extension, you can cause incoming messages to be automatically
133 # scanned for viruses. You have to modify the configuration in two places to
134 # set this up. The first of them is here, where you define the interface to
135 # your scanner. This example is typical for ClamAV; see the manual for details
136 # of what to set for other virus scanners. The second modification is in the
137 # acl_check_data access control list (see below).
138
139 # av_scanner = clamd:/tmp/clamd
140
141
142 # For spam scanning, there is a similar option that defines the interface to
143 # SpamAssassin. You do not need to set this if you are using the default, which
144 # is shown in this commented example. As for virus scanning, you must also
145 # modify the acl_check_data access control list to enable spam scanning.
146
147 # spamd_address = 127.0.0.1 783
148
149
150 # If Exim is compiled with support for TLS, you may want to enable the
151 # following options so that Exim allows clients to make encrypted
152 # connections. In the authenticators section below, there are template
153 # configurations for plaintext username/password authentication. This kind
154 # of authentication is only safe when used within a TLS connection, so the
155 # authenticators will only work if the following TLS settings are turned on
156 # as well.
157
158 # Allow any client to use TLS.
159
160 # tls_advertise_hosts = *
161
162 # Specify the location of the Exim server's TLS certificate and private key.
163 # The private key must not be encrypted (password protected). You can put
164 # the certificate and private key in the same file, in which case you only
165 # need the first setting, or in separate files, in which case you need both
166 # options.
167
168 # tls_certificate = /etc/ssl/exim.crt
169 # tls_privatekey = /etc/ssl/exim.pem
170
171 # For OpenSSL, prefer EC- over RSA-authenticated ciphers
172 # tls_require_ciphers = ECDSA:RSA:!COMPLEMENTOFDEFAULT
173
174 # In order to support roaming users who wish to send email from anywhere,
175 # you may want to make Exim listen on other ports as well as port 25, in
176 # case these users need to send email from a network that blocks port 25.
177 # The standard port for this purpose is port 587, the "message submission"
178 # port. See RFC 4409 for details. Microsoft MUAs cannot be configured to
179 # talk the message submission protocol correctly, so if you need to support
180 # them you should also allow TLS-on-connect on the traditional but
181 # non-standard port 465.
182
183 # daemon_smtp_ports = 25 : 465 : 587
184 # tls_on_connect_ports = 465
185
186
187 # Specify the domain you want to be added to all unqualified addresses
188 # here. An unqualified address is one that does not contain an "@" character
189 # followed by a domain. For example, "caesar@rome.example" is a fully qualified
190 # address, but the string "caesar" (i.e. just a login name) is an unqualified
191 # email address. Unqualified addresses are accepted only from local callers by
192 # default. See the recipient_unqualified_hosts option if you want to permit
193 # unqualified addresses from remote sources. If this option is not set, the
194 # primary_hostname value is used for qualification.
195
196 # qualify_domain =
197
198
199 # If you want unqualified recipient addresses to be qualified with a different
200 # domain to unqualified sender addresses, specify the recipient domain here.
201 # If this option is not set, the qualify_domain value is used.
202
203 # qualify_recipient =
204
205
206 # The following line must be uncommented if you want Exim to recognize
207 # addresses of the form "user@[10.11.12.13]" that is, with a "domain literal"
208 # (an IP address) instead of a named domain. The RFCs still require this form,
209 # but it makes little sense to permit mail to be sent to specific hosts by
210 # their IP address in the modern Internet. This ancient format has been used
211 # by those seeking to abuse hosts by using them for unwanted relaying. If you
212 # really do want to support domain literals, uncomment the following line, and
213 # see also the "domain_literal" router below.
214
215 # allow_domain_literals
216
217
218 # No deliveries will ever be run under the uids of users specified by
219 # never_users (a colon-separated list). An attempt to do so causes a panic
220 # error to be logged, and the delivery to be deferred. This is a paranoic
221 # safety catch. There is an even stronger safety catch in the form of the
222 # FIXED_NEVER_USERS setting in the configuration for building Exim. The list of
223 # users that it specifies is built into the binary, and cannot be changed. The
224 # option below just adds additional users to the list. The default for
225 # FIXED_NEVER_USERS is "root", but just to be absolutely sure, the default here
226 # is also "root".
227
228 # Note that the default setting means you cannot deliver mail addressed to root
229 # as if it were a normal user. This isn't usually a problem, as most sites have
230 # an alias for root that redirects such mail to a human administrator.
231
232 never_users = root
233
234
235 # The setting below causes Exim to do a reverse DNS lookup on all incoming
236 # IP calls, in order to get the true host name. If you feel this is too
237 # expensive, you can specify the networks for which a lookup is done, or
238 # remove the setting entirely.
239
240 host_lookup = *
241
242
243 # The setting below causes Exim to try to initialize the system resolver
244 # library with DNSSEC support. It has no effect if your library lacks
245 # DNSSEC support.
246
247 dns_dnssec_ok = 1
248
249
250 # The settings below cause Exim to make RFC 1413 (ident) callbacks
251 # for all incoming SMTP calls. You can limit the hosts to which these
252 # calls are made, and/or change the timeout that is used. If you set
253 # the timeout to zero, all RFC 1413 calls are disabled. RFC 1413 calls
254 # are cheap and can provide useful information for tracing problem
255 # messages, but some hosts and firewalls have problems with them.
256 # This can result in a timeout instead of an immediate refused
257 # connection, leading to delays on starting up SMTP sessions.
258 # (The default was reduced from 30s to 5s for release 4.61. and to
259 # disabled for release 4.86)
260 #
261 #rfc1413_hosts = *
262 #rfc1413_query_timeout = 5s
263
264
265 # Enable an efficiency feature. We advertise the feature; clients
266 # may request to use it. For multi-recipient mails we then can
267 # reject or accept per-user after the message is received.
268 #
269 .ifdef _HAVE_PRDR
270 prdr_enable = true
271 .endif
272
273
274 # By default, Exim expects all envelope addresses to be fully qualified, that
275 # is, they must contain both a local part and a domain. If you want to accept
276 # unqualified addresses (just a local part) from certain hosts, you can specify
277 # these hosts by setting one or both of
278 #
279 # sender_unqualified_hosts =
280 # recipient_unqualified_hosts =
281 #
282 # to control sender and recipient addresses, respectively. When this is done,
283 # unqualified addresses are qualified using the settings of qualify_domain
284 # and/or qualify_recipient (see above).
285
286
287 # Unless you run a high-volume site you probably want more logging
288 # detail than the default. Adjust to suit.
289
290 log_selector = +smtp_protocol_error +smtp_syntax_error \
291 +tls_certificate_verified
292
293
294 # If you want Exim to support the "percent hack" for certain domains,
295 # uncomment the following line and provide a list of domains. The "percent
296 # hack" is the feature by which mail addressed to x%y@z (where z is one of
297 # the domains listed) is locally rerouted to x@y and sent on. If z is not one
298 # of the "percent hack" domains, x%y is treated as an ordinary local part. This
299 # hack is rarely needed nowadays; you should not enable it unless you are sure
300 # that you really need it.
301 #
302 # percent_hack_domains =
303 #
304 # As well as setting this option you will also need to remove the test
305 # for local parts containing % in the ACL definition below.
306
307
308 # When Exim can neither deliver a message nor return it to sender, it "freezes"
309 # the delivery error message (aka "bounce message"). There are also other
310 # circumstances in which messages get frozen. They will stay on the queue for
311 # ever unless one of the following options is set.
312
313 # This option unfreezes frozen bounce messages after two days, tries
314 # once more to deliver them, and ignores any delivery failures.
315
316 ignore_bounce_errors_after = 2d
317
318 # This option cancels (removes) frozen messages that are older than a week.
319
320 timeout_frozen_after = 7d
321
322
323 # By default, messages that are waiting on Exim's queue are all held in a
324 # single directory called "input" which it itself within Exim's spool
325 # directory. (The default spool directory is specified when Exim is built, and
326 # is often /var/spool/exim/.) Exim works best when its queue is kept short, but
327 # there are circumstances where this is not always possible. If you uncomment
328 # the setting below, messages on the queue are held in 62 subdirectories of
329 # "input" instead of all in the same directory. The subdirectories are called
330 # 0, 1, ... A, B, ... a, b, ... z. This has two benefits: (1) If your file
331 # system degrades with many files in one directory, this is less likely to
332 # happen; (2) Exim can process the queue one subdirectory at a time instead of
333 # all at once, which can give better performance with large queues.
334
335 # split_spool_directory = true
336
337
338 # If you're in a part of the world where ASCII is not sufficient for most
339 # text, then you're probably familiar with RFC2047 message header extensions.
340 # By default, Exim adheres to the specification, including a limit of 76
341 # characters to a line, with encoded words fitting within a line.
342 # If you wish to use decoded headers in message filters in such a way
343 # that successful decoding of malformed messages matters, you may wish to
344 # configure Exim to be more lenient.
345 #
346 # check_rfc2047_length = false
347 #
348 # In particular, the Exim maintainers have had multiple reports of problems
349 # from Russian administrators of issues until they disable this check,
350 # because of some popular, yet buggy, mail composition software.
351
352
353 # If you wish to be strictly RFC compliant, or if you know you'll be
354 # exchanging email with systems that are not 8-bit clean, then you may
355 # wish to disable advertising 8BITMIME. Uncomment this option to do so.
356
357 # accept_8bitmime = false
358
359
360 # Exim does not make use of environment variables itself. However,
361 # libraries that Exim uses (e.g. LDAP) depend on specific environment settings.
362 # There are two lists: keep_environment for the variables we trust, and
363 # add_environment for variables we want to set to a specific value.
364 # Note that TZ is handled separately by the timezone runtime option
365 # and TIMEZONE_DEFAULT buildtime option.
366
367 # keep_environment = ^LDAP
368 # add_environment = PATH=/usr/bin::/bin
369
370
371
372 ######################################################################
373 # ACL CONFIGURATION #
374 # Specifies access control lists for incoming SMTP mail #
375 ######################################################################
376
377 begin acl
378
379 # This access control list is used for every RCPT command in an incoming
380 # SMTP message. The tests are run in order until the address is either
381 # accepted or denied.
382
383 acl_check_rcpt:
384
385 # Accept if the source is local SMTP (i.e. not over TCP/IP). We do this by
386 # testing for an empty sending host field.
387
388 accept hosts = :
389 control = dkim_disable_verify
390
391 #############################################################################
392 # The following section of the ACL is concerned with local parts that contain
393 # @ or % or ! or / or | or dots in unusual places.
394 #
395 # The characters other than dots are rarely found in genuine local parts, but
396 # are often tried by people looking to circumvent relaying restrictions.
397 # Therefore, although they are valid in local parts, these rules lock them
398 # out, as a precaution.
399 #
400 # Empty components (two dots in a row) are not valid in RFC 2822, but Exim
401 # allows them because they have been encountered. (Consider local parts
402 # constructed as "firstinitial.secondinitial.familyname" when applied to
403 # someone like me, who has no second initial.) However, a local part starting
404 # with a dot or containing /../ can cause trouble if it is used as part of a
405 # file name (e.g. for a mailing list). This is also true for local parts that
406 # contain slashes. A pipe symbol can also be troublesome if the local part is
407 # incorporated unthinkingly into a shell command line.
408 #
409 # Two different rules are used. The first one is stricter, and is applied to
410 # messages that are addressed to one of the local domains handled by this
411 # host. The line "domains = +local_domains" restricts it to domains that are
412 # defined by the "domainlist local_domains" setting above. The rule blocks
413 # local parts that begin with a dot or contain @ % ! / or |. If you have
414 # local accounts that include these characters, you will have to modify this
415 # rule.
416
417 deny message = Restricted characters in address
418 domains = +local_domains
419 local_parts = ^[.] : ^.*[@%!/|]
420
421 # The second rule applies to all other domains, and is less strict. The line
422 # "domains = !+local_domains" restricts it to domains that are NOT defined by
423 # the "domainlist local_domains" setting above. The exclamation mark is a
424 # negating operator. This rule allows your own users to send outgoing
425 # messages to sites that use slashes and vertical bars in their local parts.
426 # It blocks local parts that begin with a dot, slash, or vertical bar, but
427 # allows these characters within the local part. However, the sequence /../
428 # is barred. The use of @ % and ! is blocked, as before. The motivation here
429 # is to prevent your users (or your users' viruses) from mounting certain
430 # kinds of attack on remote sites.
431
432 deny message = Restricted characters in address
433 domains = !+local_domains
434 local_parts = ^[./|] : ^.*[@%!] : ^.*/\\.\\./
435 #############################################################################
436
437 # Accept mail to postmaster in any local domain, regardless of the source,
438 # and without verifying the sender.
439
440 accept local_parts = postmaster
441 domains = +local_domains
442
443 # Deny unless the sender address can be verified.
444
445 require verify = sender
446
447 # Accept if the message comes from one of the hosts for which we are an
448 # outgoing relay. It is assumed that such hosts are most likely to be MUAs,
449 # so we set control=submission to make Exim treat the message as a
450 # submission. It will fix up various errors in the message, for example, the
451 # lack of a Date: header line. If you are actually relaying out out from
452 # MTAs, you may want to disable this. If you are handling both relaying from
453 # MTAs and submissions from MUAs you should probably split them into two
454 # lists, and handle them differently.
455
456 # Recipient verification is omitted here, because in many cases the clients
457 # are dumb MUAs that don't cope well with SMTP error responses. If you are
458 # actually relaying out from MTAs, you should probably add recipient
459 # verification here.
460
461 # Note that, by putting this test before any DNS black list checks, you will
462 # always accept from these hosts, even if they end up on a black list. The
463 # assumption is that they are your friends, and if they get onto a black
464 # list, it is a mistake.
465
466 accept hosts = +relay_from_hosts
467 control = submission
468 control = dkim_disable_verify
469
470 # Accept if the message arrived over an authenticated connection, from
471 # any host. Again, these messages are usually from MUAs, so recipient
472 # verification is omitted, and submission mode is set. And again, we do this
473 # check before any black list tests.
474
475 accept authenticated = *
476 control = submission
477 control = dkim_disable_verify
478
479 # Insist that a HELO/EHLO was accepted.
480
481 require message = nice hosts say HELO first
482 condition = ${if def:sender_helo_name}
483
484 # Insist that any other recipient address that we accept is either in one of
485 # our local domains, or is in a domain for which we explicitly allow
486 # relaying. Any other domain is rejected as being unacceptable for relaying.
487
488 require message = relay not permitted
489 domains = +local_domains : +relay_to_domains
490
491 # We also require all accepted addresses to be verifiable. This check will
492 # do local part verification for local domains, but only check the domain
493 # for remote domains. The only way to check local parts for the remote
494 # relay domains is to use a callout (add /callout), but please read the
495 # documentation about callouts before doing this.
496
497 require verify = recipient
498
499 #############################################################################
500 # There are no default checks on DNS black lists because the domains that
501 # contain these lists are changing all the time. However, here are two
502 # examples of how you can get Exim to perform a DNS black list lookup at this
503 # point. The first one denies, whereas the second just warns.
504 #
505 # deny message = rejected because $sender_host_address is in a black list at $dnslist_domain\n$dnslist_text
506 # dnslists = black.list.example
507 #
508 # warn dnslists = black.list.example
509 # add_header = X-Warning: $sender_host_address is in a black list at $dnslist_domain
510 # log_message = found in $dnslist_domain
511 #############################################################################
512
513 #############################################################################
514 # This check is commented out because it is recognized that not every
515 # sysadmin will want to do it. If you enable it, the check performs
516 # Client SMTP Authorization (csa) checks on the sending host. These checks
517 # do DNS lookups for SRV records. The CSA proposal is currently (May 2005)
518 # an Internet draft. You can, of course, add additional conditions to this
519 # ACL statement to restrict the CSA checks to certain hosts only.
520 #
521 # require verify = csa
522 #############################################################################
523
524 #############################################################################
525 # If doing per-user content filtering then recipients with filters different
526 # to the first recipient must be deferred unless the sender talks PRDR.
527 #
528 # defer !condition = $prdr_requested
529 # condition = ${if > {0}{$receipients_count}}
530 # condition = ${if !eq {$acl_m_content_filter} \
531 # {${lookup PER_RCPT_CONTENT_FILTER}}}
532 # warn !condition = $prdr_requested
533 # condition = ${if > {0}{$receipients_count}}
534 # set acl_m_content_filter = ${lookup PER_RCPT_CONTENT_FILTER}
535 #############################################################################
536
537 # At this point, the address has passed all the checks that have been
538 # configured, so we accept it unconditionally.
539
540 accept
541
542
543 # This ACL is used once per recipient, for multi-recipient messages, if
544 # we advertised PRDR. It can be used to perform receipient-dependent
545 # header- and body- based filtering and rejections.
546 # We set a variable to record that PRDR was active used, so that checking
547 # in the data ACL can be skipped.
548
549 .ifdef _HAVE_PRDR
550 acl_check_prdr:
551 warn set acl_m_did_prdr = y
552 .endif
553
554 #############################################################################
555 # do lookup on filtering, with $local_part@$domain, deny on filter match
556 #
557 # deny set acl_m_content_filter = ${lookup PER_RCPT_CONTENT_FILTER}
558 # condition = ...
559 #############################################################################
560
561 accept
562
563 # This ACL is used after the contents of a message have been received. This
564 # is the ACL in which you can test a message's headers or body, and in
565 # particular, this is where you can invoke external virus or spam scanners.
566 # Some suggested ways of configuring these tests are shown below, commented
567 # out. Without any tests, this ACL accepts all messages. If you want to use
568 # such tests, you must ensure that Exim is compiled with the content-scanning
569 # extension (WITH_CONTENT_SCAN=yes in Local/Makefile).
570
571 acl_check_data:
572
573 # Deny if the message contains an overlong line. Per the standards
574 # we should never receive one such via SMTP.
575 #
576 deny message = maximum allowed line length is 998 octets, \
577 got $max_received_linelength
578 condition = ${if > {$max_received_linelength}{998}}
579
580 # Deny if the headers contain badly-formed addresses.
581 #
582 deny !verify = header_syntax
583 message = header syntax
584 log_message = header syntax ($acl_verify_message)
585
586 # Deny if the message contains a virus. Before enabling this check, you
587 # must install a virus scanner and set the av_scanner option above.
588 #
589 # deny malware = *
590 # message = This message contains a virus ($malware_name).
591
592 # Add headers to a message if it is judged to be spam. Before enabling this,
593 # you must install SpamAssassin. You may also need to set the spamd_address
594 # option above.
595 #
596 # warn spam = nobody
597 # add_header = X-Spam_score: $spam_score\n\
598 # X-Spam_score_int: $spam_score_int\n\
599 # X-Spam_bar: $spam_bar\n\
600 # X-Spam_report: $spam_report
601
602 #############################################################################
603 # No more tests if PRDR was actively used.
604 # accept condition = ${if def:acl_m_did_prdr}
605 #
606 # To get here, all message recipients must have identical per-user
607 # content filtering (enforced by RCPT ACL). Do lookup for filter
608 # and deny on match.
609 #
610 # deny set acl_m_content_filter = ${lookup PER_RCPT_CONTENT_FILTER}
611 # condition = ...
612 #############################################################################
613
614
615 # Accept the message.
616
617 accept
618
619
620
621 ######################################################################
622 # ROUTERS CONFIGURATION #
623 # Specifies how addresses are handled #
624 ######################################################################
625 # THE ORDER IN WHICH THE ROUTERS ARE DEFINED IS IMPORTANT! #
626 # An address is passed to each router in turn until it is accepted. #
627 ######################################################################
628
629 begin routers
630
631 # This router routes to remote hosts over SMTP by explicit IP address,
632 # when an email address is given in "domain literal" form, for example,
633 # <user@[192.168.35.64]>. The RFCs require this facility. However, it is
634 # little-known these days, and has been exploited by evil people seeking
635 # to abuse SMTP relays. Consequently it is commented out in the default
636 # configuration. If you uncomment this router, you also need to uncomment
637 # allow_domain_literals above, so that Exim can recognize the syntax of
638 # domain literal addresses.
639
640 # domain_literal:
641 # driver = ipliteral
642 # domains = ! +local_domains
643 # transport = remote_smtp
644
645
646 # This router can be used when you want to send all mail to a
647 # server which handles DNS lookups for you; an ISP will typically run such
648 # a server for their customers. The hostname in route_data comes from the
649 # macro defined at the top of the file. If not defined, then we'll use the
650 # dnslookup router below instead.
651 # Beware that the hostname is specified again in the Transport.
652
653 .ifdef ROUTER_SMARTHOST
654
655 smarthost:
656 driver = manualroute
657 domains = ! +local_domains
658 transport = smarthost_smtp
659 route_data = ROUTER_SMARTHOST
660 ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
661 no_more
662
663 .else
664
665 # This router routes addresses that are not in local domains by doing a DNS
666 # lookup on the domain name. The exclamation mark that appears in "domains = !
667 # +local_domains" is a negating operator, that is, it can be read as "not". The
668 # recipient's domain must not be one of those defined by "domainlist
669 # local_domains" above for this router to be used.
670 #
671 # If the router is used, any domain that resolves to 0.0.0.0 or to a loopback
672 # interface address (127.0.0.0/8) is treated as if it had no DNS entry. Note
673 # that 0.0.0.0 is the same as 0.0.0.0/32, which is commonly treated as the
674 # local host inside the network stack. It is not 0.0.0.0/0, the default route.
675 # If the DNS lookup fails, no further routers are tried because of the no_more
676 # setting, and consequently the address is unrouteable.
677
678 dnslookup:
679 driver = dnslookup
680 domains = ! +local_domains
681 transport = remote_smtp
682 ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
683 # if ipv6-enabled then instead use:
684 # ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
685 dnssec_request_domains = *
686 no_more
687
688 # This closes the ROUTER_SMARTHOST ifdef around the choice of routing for
689 # off-site mail.
690 .endif
691
692
693 # The remaining routers handle addresses in the local domain(s), that is those
694 # domains that are defined by "domainlist local_domains" above.
695
696
697 # This router handles aliasing using a linearly searched alias file with the
698 # name SYSTEM_ALIASES_FILE. When this configuration is installed automatically,
699 # the name gets inserted into this file from whatever is set in Exim's
700 # build-time configuration. The default path is the traditional /etc/aliases.
701 # If you install this configuration by hand, you need to specify the correct
702 # path in the "data" setting below.
703 #
704 ##### NB You must ensure that the alias file exists. It used to be the case
705 ##### NB that every Unix had that file, because it was the Sendmail default.
706 ##### NB These days, there are systems that don't have it. Your aliases
707 ##### NB file should at least contain an alias for "postmaster".
708 #
709 # If any of your aliases expand to pipes or files, you will need to set
710 # up a user and a group for these deliveries to run under. You can do
711 # this by uncommenting the "user" option below (changing the user name
712 # as appropriate) and adding a "group" option if necessary. Alternatively, you
713 # can specify "user" on the transports that are used. Note that the transports
714 # listed below are the same as are used for .forward files; you might want
715 # to set up different ones for pipe and file deliveries from aliases.
716
717 system_aliases:
718 driver = redirect
719 allow_fail
720 allow_defer
721 data = ${lookup{$local_part}lsearch{SYSTEM_ALIASES_FILE}}
722 # user = exim
723 file_transport = address_file
724 pipe_transport = address_pipe
725
726
727 # This router handles forwarding using traditional .forward files in users'
728 # home directories. If you want it also to allow mail filtering when a forward
729 # file starts with the string "# Exim filter" or "# Sieve filter", uncomment
730 # the "allow_filter" option.
731
732 # The no_verify setting means that this router is skipped when Exim is
733 # verifying addresses. Similarly, no_expn means that this router is skipped if
734 # Exim is processing an EXPN command.
735
736 # If you want this router to treat local parts with suffixes introduced by "-"
737 # or "+" characters as if the suffixes did not exist, uncomment the two local_
738 # part_suffix options. Then, for example, xxxx-foo@your.domain will be treated
739 # in the same way as xxxx@your.domain by this router. Because this router is
740 # not used for verification, if you choose to uncomment those options, then you
741 # will *need* to make the same change to the localuser router. (There are
742 # other approaches, if this is undesirable, but they add complexity).
743
744 # The check_ancestor option means that if the forward file generates an
745 # address that is an ancestor of the current one, the current one gets
746 # passed on instead. This covers the case where A is aliased to B and B
747 # has a .forward file pointing to A.
748
749 # The three transports specified at the end are those that are used when
750 # forwarding generates a direct delivery to a file, or to a pipe, or sets
751 # up an auto-reply, respectively.
752
753 userforward:
754 driver = redirect
755 check_local_user
756 # local_part_suffix = +* : -*
757 # local_part_suffix_optional
758 file = $home/.forward
759 # allow_filter
760 no_verify
761 no_expn
762 check_ancestor
763 file_transport = address_file
764 pipe_transport = address_pipe
765 reply_transport = address_reply
766
767
768 # This router matches local user mailboxes. If the router fails, the error
769 # message is "Unknown user".
770
771 # If you want this router to treat local parts with suffixes introduced by "-"
772 # or "+" characters as if the suffixes did not exist, uncomment the two local_
773 # part_suffix options. Then, for example, xxxx-foo@your.domain will be treated
774 # in the same way as xxxx@your.domain by this router.
775
776 localuser:
777 driver = accept
778 check_local_user
779 # local_part_suffix = +* : -*
780 # local_part_suffix_optional
781 transport = local_delivery
782 cannot_route_message = Unknown user
783
784
785
786 ######################################################################
787 # TRANSPORTS CONFIGURATION #
788 ######################################################################
789 # ORDER DOES NOT MATTER #
790 # Only one appropriate transport is called for each delivery. #
791 ######################################################################
792
793 # A transport is used only when referenced from a router that successfully
794 # handles an address.
795
796 begin transports
797
798
799 # This transport is used for delivering messages over SMTP connections.
800 # Refuse to send any message with over-long lines, which could have
801 # been received other than via SMTP. The use of message_size_limit to
802 # enforce this is a red herring.
803
804 remote_smtp:
805 driver = smtp
806 message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
807 .ifdef _HAVE_DANE
808 dnssec_request_domains = *
809 hosts_try_dane = *
810 .endif
811 .ifdef _HAVE_PRDR
812 hosts_try_prdr = *
813 .endif
814
815
816 # This transport is used for delivering messages to a smarthost, if the
817 # smarthost router is enabled. This starts from the same basis as
818 # "remote_smtp" but then turns on various security options, because
819 # we assume that if you're told "use smarthost.example.org as the smarthost"
820 # then there will be TLS available, with a verifiable certificate for that
821 # hostname, using decent TLS.
822
823 smarthost_smtp:
824 driver = smtp
825 message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
826 multi_domain
827 #
828 .ifdef _HAVE_TLS
829 # Comment out any of these which you have to, then file a Support
830 # request with your smarthost provider to get things fixed:
831 hosts_require_tls = *
832 tls_verify_hosts = *
833 # As long as tls_verify_hosts is enabled, this won't matter, but if you
834 # have to comment it out then this will at least log whether you succeed
835 # or not:
836 tls_try_verify_hosts = *
837 #
838 # The SNI name should match the name which we'll expect to verify;
839 # many mail systems don't use SNI and this doesn't matter, but if it does,
840 # we need to send a name which the remote site will recognize.
841 # This _should_ be the name which the smarthost operators specified as
842 # the hostname for sending your mail to.
843 tls_sni = ROUTER_SMARTHOST
844 #
845 .ifdef _HAVE_OPENSSL
846 tls_require_ciphers = HIGH:!aNULL:@STRENGTH
847 .endif
848 .ifdef _HAVE_GNUTLS
849 tls_require_ciphers = SECURE192:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1
850 .endif
851 .endif
852 .ifdef _HAVE_PRDR
853 hosts_try_prdr = *
854 .endif
855
856
857 # This transport is used for local delivery to user mailboxes in traditional
858 # BSD mailbox format. By default it will be run under the uid and gid of the
859 # local user, and requires the sticky bit to be set on the /var/mail directory.
860 # Some systems use the alternative approach of running mail deliveries under a
861 # particular group instead of using the sticky bit. The commented options below
862 # show how this can be done.
863
864 local_delivery:
865 driver = appendfile
866 file = /var/mail/$local_part
867 delivery_date_add
868 envelope_to_add
869 return_path_add
870 # group = mail
871 # mode = 0660
872
873
874 # This transport is used for handling pipe deliveries generated by alias or
875 # .forward files. If the pipe generates any standard output, it is returned
876 # to the sender of the message as a delivery error. Set return_fail_output
877 # instead of return_output if you want this to happen only when the pipe fails
878 # to complete normally. You can set different transports for aliases and
879 # forwards if you want to - see the references to address_pipe in the routers
880 # section above.
881
882 address_pipe:
883 driver = pipe
884 return_output
885
886
887 # This transport is used for handling deliveries directly to files that are
888 # generated by aliasing or forwarding.
889
890 address_file:
891 driver = appendfile
892 delivery_date_add
893 envelope_to_add
894 return_path_add
895
896
897 # This transport is used for handling autoreplies generated by the filtering
898 # option of the userforward router.
899
900 address_reply:
901 driver = autoreply
902
903
904
905 ######################################################################
906 # RETRY CONFIGURATION #
907 ######################################################################
908
909 begin retry
910
911 # This single retry rule applies to all domains and all errors. It specifies
912 # retries every 15 minutes for 2 hours, then increasing retry intervals,
913 # starting at 1 hour and increasing each time by a factor of 1.5, up to 16
914 # hours, then retries every 6 hours until 4 days have passed since the first
915 # failed delivery.
916
917 # WARNING: If you do not have any retry rules at all (this section of the
918 # configuration is non-existent or empty), Exim will not do any retries of
919 # messages that fail to get delivered at the first attempt. The effect will
920 # be to treat temporary errors as permanent. Therefore, DO NOT remove this
921 # retry rule unless you really don't want any retries.
922
923 # Address or Domain Error Retries
924 # ----------------- ----- -------
925
926 * * F,2h,15m; G,16h,1h,1.5; F,4d,6h
927
928
929
930 ######################################################################
931 # REWRITE CONFIGURATION #
932 ######################################################################
933
934 # There are no rewriting specifications in this default configuration file.
935
936 begin rewrite
937
938
939
940 ######################################################################
941 # AUTHENTICATION CONFIGURATION #
942 ######################################################################
943
944 # The following authenticators support plaintext username/password
945 # authentication using the standard PLAIN mechanism and the traditional
946 # but non-standard LOGIN mechanism, with Exim acting as the server.
947 # PLAIN and LOGIN are enough to support most MUA software.
948 #
949 # These authenticators are not complete: you need to change the
950 # server_condition settings to specify how passwords are verified.
951 # They are set up to offer authentication to the client only if the
952 # connection is encrypted with TLS, so you also need to add support
953 # for TLS. See the global configuration options section at the start
954 # of this file for more about TLS.
955 #
956 # The default RCPT ACL checks for successful authentication, and will accept
957 # messages from authenticated users from anywhere on the Internet.
958
959 begin authenticators
960
961 # PLAIN authentication has no server prompts. The client sends its
962 # credentials in one lump, containing an authorization ID (which we do not
963 # use), an authentication ID, and a password. The latter two appear as
964 # $auth2 and $auth3 in the configuration and should be checked against a
965 # valid username and password. In a real configuration you would typically
966 # use $auth2 as a lookup key, and compare $auth3 against the result of the
967 # lookup, perhaps using the crypteq{}{} condition.
968
969 #PLAIN:
970 # driver = plaintext
971 # server_set_id = $auth2
972 # server_prompts = :
973 # server_condition = Authentication is not yet configured
974 # server_advertise_condition = ${if def:tls_in_cipher }
975
976 # LOGIN authentication has traditional prompts and responses. There is no
977 # authorization ID in this mechanism, so unlike PLAIN the username and
978 # password are $auth1 and $auth2. Apart from that you can use the same
979 # server_condition setting for both authenticators.
980
981 #LOGIN:
982 # driver = plaintext
983 # server_set_id = $auth1
984 # server_prompts = <| Username: | Password:
985 # server_condition = Authentication is not yet configured
986 # server_advertise_condition = ${if def:tls_in_cipher }
987
988
989 ######################################################################
990 # CONFIGURATION FOR local_scan() #
991 ######################################################################
992
993 # If you have built Exim to include a local_scan() function that contains
994 # tables for private options, you can define those options here. Remember to
995 # uncomment the "begin" line. It is commented by default because it provokes
996 # an error with Exim binaries that are not built with LOCAL_SCAN_HAS_OPTIONS
997 # set in the Local/Makefile.
998
999 # begin local_scan
1000
1001
1002 # End of Exim configuration file