Grammar changes in docs
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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
20f0f788 12# from the Exim ftp sites. The manual is also online at the Exim website.
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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######################################################################
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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######################################################################
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53# MAIN CONFIGURATION SETTINGS #
54######################################################################
f26587cb 55#
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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
70domainlist local_domains = @
71domainlist relay_to_domains =
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72hostlist 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.)
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75
76# Most straightforward access control requirements can be obtained by
53394084 77# appropriate settings of the above options. In more complicated situations,
92db8b2d 78# you may need to modify the Access Control Lists (ACLs) which appear later in
53394084 79# this file.
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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#
ff284120 109# hostlist relay_from_hosts = <; 127.0.0.1 ; ::1 ; 192.168.0.0/16
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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
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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.
059ec3d9 116
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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
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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:
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121
122acl_smtp_rcpt = acl_check_rcpt
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123acl_smtp_data = acl_check_data
124
125# You should not change those settings until you understand how ACLs work.
126
127
128# If you are running a version of Exim that was compiled with the content-
129# scanning extension, you can cause incoming messages to be automatically
130# scanned for viruses. You have to modify the configuration in two places to
131# set this up. The first of them is here, where you define the interface to
132# your scanner. This example is typical for ClamAV; see the manual for details
133# of what to set for other virus scanners. The second modification is in the
134# acl_check_data access control list (see below).
059ec3d9 135
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136# av_scanner = clamd:/tmp/clamd
137
138
139# For spam scanning, there is a similar option that defines the interface to
140# SpamAssassin. You do not need to set this if you are using the default, which
141# is shown in this commented example. As for virus scanning, you must also
142# modify the acl_check_data access control list to enable spam scanning.
143
144# spamd_address = 127.0.0.1 783
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145
146
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147# If Exim is compiled with support for TLS, you may want to enable the
148# following options so that Exim allows clients to make encrypted
149# connections. In the authenticators section below, there are template
150# configurations for plaintext username/password authentication. This kind
151# of authentication is only safe when used within a TLS connection, so the
152# authenticators will only work if the following TLS settings are turned on
153# as well.
154
155# Allow any client to use TLS.
156
157# tls_advertise_hosts = *
158
159# Specify the location of the Exim server's TLS certificate and private key.
160# The private key must not be encrypted (password protected). You can put
161# the certificate and private key in the same file, in which case you only
162# need the first setting, or in separate files, in which case you need both
163# options.
164
165# tls_certificate = /etc/ssl/exim.crt
166# tls_privatekey = /etc/ssl/exim.pem
167
ba86e143 168# For OpenSSL, prefer EC- over RSA-authenticated ciphers
1fa62f99 169# tls_require_ciphers = ECDSA:RSA:!COMPLEMENTOFDEFAULT
ba86e143 170
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171# In order to support roaming users who wish to send email from anywhere,
172# you may want to make Exim listen on other ports as well as port 25, in
173# case these users need to send email from a network that blocks port 25.
174# The standard port for this purpose is port 587, the "message submission"
175# port. See RFC 4409 for details. Microsoft MUAs cannot be configured to
176# talk the message submission protocol correctly, so if you need to support
177# them you should also allow TLS-on-connect on the traditional but
178# non-standard port 465.
179
180# daemon_smtp_ports = 25 : 465 : 587
181# tls_on_connect_ports = 465
182
183
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184# Specify the domain you want to be added to all unqualified addresses
185# here. An unqualified address is one that does not contain an "@" character
186# followed by a domain. For example, "caesar@rome.example" is a fully qualified
187# address, but the string "caesar" (i.e. just a login name) is an unqualified
188# email address. Unqualified addresses are accepted only from local callers by
189# default. See the recipient_unqualified_hosts option if you want to permit
190# unqualified addresses from remote sources. If this option is not set, the
191# primary_hostname value is used for qualification.
192
193# qualify_domain =
194
195
196# If you want unqualified recipient addresses to be qualified with a different
197# domain to unqualified sender addresses, specify the recipient domain here.
198# If this option is not set, the qualify_domain value is used.
199
200# qualify_recipient =
201
202
203# The following line must be uncommented if you want Exim to recognize
204# addresses of the form "user@[10.11.12.13]" that is, with a "domain literal"
205# (an IP address) instead of a named domain. The RFCs still require this form,
206# but it makes little sense to permit mail to be sent to specific hosts by
207# their IP address in the modern Internet. This ancient format has been used
208# by those seeking to abuse hosts by using them for unwanted relaying. If you
209# really do want to support domain literals, uncomment the following line, and
210# see also the "domain_literal" router below.
211
212# allow_domain_literals
213
214
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215# No deliveries will ever be run under the uids of users specified by
216# never_users (a colon-separated list). An attempt to do so causes a panic
217# error to be logged, and the delivery to be deferred. This is a paranoic
218# safety catch. There is an even stronger safety catch in the form of the
219# FIXED_NEVER_USERS setting in the configuration for building Exim. The list of
220# users that it specifies is built into the binary, and cannot be changed. The
221# option below just adds additional users to the list. The default for
222# FIXED_NEVER_USERS is "root", but just to be absolutely sure, the default here
223# is also "root".
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224
225# Note that the default setting means you cannot deliver mail addressed to root
226# as if it were a normal user. This isn't usually a problem, as most sites have
227# an alias for root that redirects such mail to a human administrator.
228
229never_users = root
230
231
232# The setting below causes Exim to do a reverse DNS lookup on all incoming
233# IP calls, in order to get the true host name. If you feel this is too
234# expensive, you can specify the networks for which a lookup is done, or
235# remove the setting entirely.
236
237host_lookup = *
238
239
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240# The setting below causes Exim to try to initialize the system resolver
241# library with DNSSEC support. It has no effect if your library lacks
242# DNSSEC support.
243
244dns_dnssec_ok = 1
245
246
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247# The settings below cause Exim to make RFC 1413 (ident) callbacks
248# for all incoming SMTP calls. You can limit the hosts to which these
249# calls are made, and/or change the timeout that is used. If you set
250# the timeout to zero, all RFC 1413 calls are disabled. RFC 1413 calls
251# are cheap and can provide useful information for tracing problem
252# messages, but some hosts and firewalls have problems with them.
253# This can result in a timeout instead of an immediate refused
254# connection, leading to delays on starting up SMTP sessions.
255# (The default was reduced from 30s to 5s for release 4.61. and to
256# disabled for release 4.86)
257#
258#rfc1413_hosts = *
259#rfc1413_query_timeout = 5s
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260
261
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262# Enable an efficiency feature. We advertise the feature; clients
263# may request to use it. For multi-recipient mails we then can
264# reject or accept per-user after the message is received.
265#
266prdr_enable = true
267
268
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269# By default, Exim expects all envelope addresses to be fully qualified, that
270# is, they must contain both a local part and a domain. If you want to accept
271# unqualified addresses (just a local part) from certain hosts, you can specify
272# these hosts by setting one or both of
273#
274# sender_unqualified_hosts =
275# recipient_unqualified_hosts =
276#
277# to control sender and recipient addresses, respectively. When this is done,
278# unqualified addresses are qualified using the settings of qualify_domain
279# and/or qualify_recipient (see above).
280
281
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282# Unless you run a high-volume site you probably want more logging
283# detail than the default. Adjust to suit.
284
285log_selector = +smtp_protocol_error +smtp_syntax_error \
286 +tls_certificate_verified
287
288
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289# If you want Exim to support the "percent hack" for certain domains,
290# uncomment the following line and provide a list of domains. The "percent
291# hack" is the feature by which mail addressed to x%y@z (where z is one of
292# the domains listed) is locally rerouted to x@y and sent on. If z is not one
293# of the "percent hack" domains, x%y is treated as an ordinary local part. This
294# hack is rarely needed nowadays; you should not enable it unless you are sure
295# that you really need it.
296#
297# percent_hack_domains =
298#
299# As well as setting this option you will also need to remove the test
300# for local parts containing % in the ACL definition below.
301
302
303# When Exim can neither deliver a message nor return it to sender, it "freezes"
304# the delivery error message (aka "bounce message"). There are also other
305# circumstances in which messages get frozen. They will stay on the queue for
306# ever unless one of the following options is set.
307
308# This option unfreezes frozen bounce messages after two days, tries
309# once more to deliver them, and ignores any delivery failures.
310
311ignore_bounce_errors_after = 2d
312
313# This option cancels (removes) frozen messages that are older than a week.
314
315timeout_frozen_after = 7d
316
317
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318# By default, messages that are waiting on Exim's queue are all held in a
319# single directory called "input" which it itself within Exim's spool
320# directory. (The default spool directory is specified when Exim is built, and
321# is often /var/spool/exim/.) Exim works best when its queue is kept short, but
322# there are circumstances where this is not always possible. If you uncomment
323# the setting below, messages on the queue are held in 62 subdirectories of
324# "input" instead of all in the same directory. The subdirectories are called
325# 0, 1, ... A, B, ... a, b, ... z. This has two benefits: (1) If your file
326# system degrades with many files in one directory, this is less likely to
327# happen; (2) Exim can process the queue one subdirectory at a time instead of
328# all at once, which can give better performance with large queues.
329
330# split_spool_directory = true
331
332
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333# If you're in a part of the world where ASCII is not sufficient for most
334# text, then you're probably familiar with RFC2047 message header extensions.
335# By default, Exim adheres to the specification, including a limit of 76
336# characters to a line, with encoded words fitting within a line.
337# If you wish to use decoded headers in message filters in such a way
338# that successful decoding of malformed messages matters, you may wish to
339# configure Exim to be more lenient.
340#
341# check_rfc2047_length = false
342#
343# In particular, the Exim maintainers have had multiple reports of problems
344# from Russian administrators of issues until they disable this check,
345# because of some popular, yet buggy, mail composition software.
346
059ec3d9 347
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348# If you wish to be strictly RFC compliant, or if you know you'll be
349# exchanging email with systems that are not 8-bit clean, then you may
350# wish to disable advertising 8BITMIME. Uncomment this option to do so.
351
352# accept_8bitmime = false
353
354
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355# Exim does not make use of environment variables itself. However,
356# libraries that Exim uses (e.g. LDAP) depend on specific environment settings.
357# There are two lists: keep_environment for the variables we trust, and
358# add_environment for variables we want to set to a specific value.
4c04137d 359# Note that TZ is handled separately by the timezone runtime option
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360# and TIMEZONE_DEFAULT buildtime option.
361
362# keep_environment = ^LDAP
363# add_environment = PATH=/usr/bin::/bin
364
365
366
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367######################################################################
368# ACL CONFIGURATION #
369# Specifies access control lists for incoming SMTP mail #
370######################################################################
371
372begin acl
373
374# This access control list is used for every RCPT command in an incoming
375# SMTP message. The tests are run in order until the address is either
376# accepted or denied.
377
378acl_check_rcpt:
379
380 # Accept if the source is local SMTP (i.e. not over TCP/IP). We do this by
381 # testing for an empty sending host field.
382
383 accept hosts = :
94f85d3e 384 control = dkim_disable_verify
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385
386 #############################################################################
387 # The following section of the ACL is concerned with local parts that contain
388 # @ or % or ! or / or | or dots in unusual places.
389 #
390 # The characters other than dots are rarely found in genuine local parts, but
391 # are often tried by people looking to circumvent relaying restrictions.
392 # Therefore, although they are valid in local parts, these rules lock them
393 # out, as a precaution.
394 #
395 # Empty components (two dots in a row) are not valid in RFC 2822, but Exim
396 # allows them because they have been encountered. (Consider local parts
397 # constructed as "firstinitial.secondinitial.familyname" when applied to
398 # someone like me, who has no second initial.) However, a local part starting
399 # with a dot or containing /../ can cause trouble if it is used as part of a
400 # file name (e.g. for a mailing list). This is also true for local parts that
401 # contain slashes. A pipe symbol can also be troublesome if the local part is
402 # incorporated unthinkingly into a shell command line.
403 #
404 # Two different rules are used. The first one is stricter, and is applied to
405 # messages that are addressed to one of the local domains handled by this
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406 # host. The line "domains = +local_domains" restricts it to domains that are
407 # defined by the "domainlist local_domains" setting above. The rule blocks
408 # local parts that begin with a dot or contain @ % ! / or |. If you have
409 # local accounts that include these characters, you will have to modify this
410 # rule.
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411
412 deny message = Restricted characters in address
413 domains = +local_domains
414 local_parts = ^[.] : ^.*[@%!/|]
415
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416 # The second rule applies to all other domains, and is less strict. The line
417 # "domains = !+local_domains" restricts it to domains that are NOT defined by
418 # the "domainlist local_domains" setting above. The exclamation mark is a
419 # negating operator. This rule allows your own users to send outgoing
420 # messages to sites that use slashes and vertical bars in their local parts.
421 # It blocks local parts that begin with a dot, slash, or vertical bar, but
422 # allows these characters within the local part. However, the sequence /../
423 # is barred. The use of @ % and ! is blocked, as before. The motivation here
424 # is to prevent your users (or your users' viruses) from mounting certain
425 # kinds of attack on remote sites.
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426
427 deny message = Restricted characters in address
428 domains = !+local_domains
429 local_parts = ^[./|] : ^.*[@%!] : ^.*/\\.\\./
430 #############################################################################
431
432 # Accept mail to postmaster in any local domain, regardless of the source,
433 # and without verifying the sender.
434
435 accept local_parts = postmaster
436 domains = +local_domains
437
438 # Deny unless the sender address can be verified.
439
440 require verify = sender
441
5de37277 442 # Accept if the message comes from one of the hosts for which we are an
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443 # outgoing relay. It is assumed that such hosts are most likely to be MUAs,
444 # so we set control=submission to make Exim treat the message as a
445 # submission. It will fix up various errors in the message, for example, the
446 # lack of a Date: header line. If you are actually relaying out out from
447 # MTAs, you may want to disable this. If you are handling both relaying from
448 # MTAs and submissions from MUAs you should probably split them into two
449 # lists, and handle them differently.
450
451 # Recipient verification is omitted here, because in many cases the clients
452 # are dumb MUAs that don't cope well with SMTP error responses. If you are
453 # actually relaying out from MTAs, you should probably add recipient
454 # verification here.
455
456 # Note that, by putting this test before any DNS black list checks, you will
457 # always accept from these hosts, even if they end up on a black list. The
458 # assumption is that they are your friends, and if they get onto a black
459 # list, it is a mistake.
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460
461 accept hosts = +relay_from_hosts
cc38ddbf 462 control = submission
94f85d3e 463 control = dkim_disable_verify
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464
465 # Accept if the message arrived over an authenticated connection, from
466 # any host. Again, these messages are usually from MUAs, so recipient
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467 # verification is omitted, and submission mode is set. And again, we do this
468 # check before any black list tests.
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469
470 accept authenticated = *
cc38ddbf 471 control = submission
94f85d3e 472 control = dkim_disable_verify
5de37277 473
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474 # Insist that a HELO/EHLO was accepted.
475
476 require message = nice hosts say HELO first
477 condition = ${if def:sender_helo_name}
478
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479 # Insist that any other recipient address that we accept is either in one of
480 # our local domains, or is in a domain for which we explicitly allow
481 # relaying. Any other domain is rejected as being unacceptable for relaying.
482
483 require message = relay not permitted
8bffe342 484 domains = +local_domains : +relay_to_domains
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485
486 # We also require all accepted addresses to be verifiable. This check will
487 # do local part verification for local domains, but only check the domain
488 # for remote domains. The only way to check local parts for the remote
489 # relay domains is to use a callout (add /callout), but please read the
490 # documentation about callouts before doing this.
491
492 require verify = recipient
493
059ec3d9 494 #############################################################################
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495 # There are no default checks on DNS black lists because the domains that
496 # contain these lists are changing all the time. However, here are two
497 # examples of how you can get Exim to perform a DNS black list lookup at this
498 # point. The first one denies, whereas the second just warns.
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499 #
500 # deny message = rejected because $sender_host_address is in a black list at $dnslist_domain\n$dnslist_text
501 # dnslists = black.list.example
502 #
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503 # warn dnslists = black.list.example
504 # add_header = X-Warning: $sender_host_address is in a black list at $dnslist_domain
059ec3d9 505 # log_message = found in $dnslist_domain
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506 #############################################################################
507
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508 #############################################################################
509 # This check is commented out because it is recognized that not every
510 # sysadmin will want to do it. If you enable it, the check performs
511 # Client SMTP Authorization (csa) checks on the sending host. These checks
512 # do DNS lookups for SRV records. The CSA proposal is currently (May 2005)
513 # an Internet draft. You can, of course, add additional conditions to this
514 # ACL statement to restrict the CSA checks to certain hosts only.
515 #
516 # require verify = csa
517 #############################################################################
518
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519 # At this point, the address has passed all the checks that have been
520 # configured, so we accept it unconditionally.
059ec3d9 521
9ecb03f3 522 accept
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523
524
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525# This ACL is used after the contents of a message have been received. This
526# is the ACL in which you can test a message's headers or body, and in
527# particular, this is where you can invoke external virus or spam scanners.
528# Some suggested ways of configuring these tests are shown below, commented
529# out. Without any tests, this ACL accepts all messages. If you want to use
530# such tests, you must ensure that Exim is compiled with the content-scanning
531# extension (WITH_CONTENT_SCAN=yes in Local/Makefile).
532
533acl_check_data:
534
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535 # Deny if the message contains an overlong line. Per the standards
536 # we should never receive one such via SMTP.
537 #
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538 deny message = maximum allowed line length is 998 octets, \
539 got $max_received_linelength
540 condition = ${if > {$max_received_linelength}{998}}
8c952127 541
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542 # Deny if the headers contain badly-formed addresses.
543 #
544 deny !verify = header_syntax
545 message = header syntax
546 log_message = header syntax ($acl_verify_message)
547
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548 # Deny if the message contains a virus. Before enabling this check, you
549 # must install a virus scanner and set the av_scanner option above.
550 #
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551 # deny malware = *
552 # message = This message contains a virus ($malware_name).
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553
554 # Add headers to a message if it is judged to be spam. Before enabling this,
555 # you must install SpamAssassin. You may also need to set the spamd_address
556 # option above.
557 #
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558 # warn spam = nobody
559 # add_header = X-Spam_score: $spam_score\n\
560 # X-Spam_score_int: $spam_score_int\n\
561 # X-Spam_bar: $spam_bar\n\
562 # X-Spam_report: $spam_report
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563
564 # Accept the message.
565
566 accept
567
568
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569
570######################################################################
571# ROUTERS CONFIGURATION #
572# Specifies how addresses are handled #
573######################################################################
574# THE ORDER IN WHICH THE ROUTERS ARE DEFINED IS IMPORTANT! #
575# An address is passed to each router in turn until it is accepted. #
576######################################################################
577
578begin routers
579
580# This router routes to remote hosts over SMTP by explicit IP address,
581# when an email address is given in "domain literal" form, for example,
582# <user@[192.168.35.64]>. The RFCs require this facility. However, it is
583# little-known these days, and has been exploited by evil people seeking
584# to abuse SMTP relays. Consequently it is commented out in the default
585# configuration. If you uncomment this router, you also need to uncomment
586# allow_domain_literals above, so that Exim can recognize the syntax of
587# domain literal addresses.
588
589# domain_literal:
590# driver = ipliteral
591# domains = ! +local_domains
592# transport = remote_smtp
593
594
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595# This router can be used when you want to send all mail to a
596# server which handles DNS lookups for you; an ISP will typically run such
597# a server for their customers. The hostname in route_data comes from the
598# macro defined at the top of the file. If not defined, then we'll use the
599# dnslookup router below instead.
600# Beware that the hostname is specified again in the Transport.
601
602.ifdef ROUTER_SMARTHOST
603
604smarthost:
605 driver = manualroute
606 domains = ! +local_domains
607 transport = smarthost_smtp
608 route_data = ROUTER_SMARTHOST
609 ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
610 no_more
611
612.else
613
059ec3d9 614# This router routes addresses that are not in local domains by doing a DNS
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615# lookup on the domain name. The exclamation mark that appears in "domains = !
616# +local_domains" is a negating operator, that is, it can be read as "not". The
617# recipient's domain must not be one of those defined by "domainlist
618# local_domains" above for this router to be used.
619#
620# If the router is used, any domain that resolves to 0.0.0.0 or to a loopback
621# interface address (127.0.0.0/8) is treated as if it had no DNS entry. Note
622# that 0.0.0.0 is the same as 0.0.0.0/32, which is commonly treated as the
623# local host inside the network stack. It is not 0.0.0.0/0, the default route.
624# If the DNS lookup fails, no further routers are tried because of the no_more
625# setting, and consequently the address is unrouteable.
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626
627dnslookup:
628 driver = dnslookup
629 domains = ! +local_domains
630 transport = remote_smtp
631 ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
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632# if ipv6-enabled then instead use:
633# ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
bdf9ce82 634 dnssec_request_domains = *
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635 no_more
636
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637# This closes the ROUTER_SMARTHOST ifdef around the choice of routing for
638# off-site mail.
639.endif
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640
641
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642# The remaining routers handle addresses in the local domain(s), that is those
643# domains that are defined by "domainlist local_domains" above.
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644
645
646# This router handles aliasing using a linearly searched alias file with the
647# name SYSTEM_ALIASES_FILE. When this configuration is installed automatically,
648# the name gets inserted into this file from whatever is set in Exim's
649# build-time configuration. The default path is the traditional /etc/aliases.
650# If you install this configuration by hand, you need to specify the correct
651# path in the "data" setting below.
652#
653##### NB You must ensure that the alias file exists. It used to be the case
654##### NB that every Unix had that file, because it was the Sendmail default.
655##### NB These days, there are systems that don't have it. Your aliases
656##### NB file should at least contain an alias for "postmaster".
657#
658# If any of your aliases expand to pipes or files, you will need to set
659# up a user and a group for these deliveries to run under. You can do
660# this by uncommenting the "user" option below (changing the user name
661# as appropriate) and adding a "group" option if necessary. Alternatively, you
662# can specify "user" on the transports that are used. Note that the transports
663# listed below are the same as are used for .forward files; you might want
664# to set up different ones for pipe and file deliveries from aliases.
665
666system_aliases:
667 driver = redirect
668 allow_fail
669 allow_defer
670 data = ${lookup{$local_part}lsearch{SYSTEM_ALIASES_FILE}}
671# user = exim
672 file_transport = address_file
673 pipe_transport = address_pipe
674
675
676# This router handles forwarding using traditional .forward files in users'
677# home directories. If you want it also to allow mail filtering when a forward
678# file starts with the string "# Exim filter" or "# Sieve filter", uncomment
679# the "allow_filter" option.
680
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681# The no_verify setting means that this router is skipped when Exim is
682# verifying addresses. Similarly, no_expn means that this router is skipped if
683# Exim is processing an EXPN command.
684
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685# If you want this router to treat local parts with suffixes introduced by "-"
686# or "+" characters as if the suffixes did not exist, uncomment the two local_
687# part_suffix options. Then, for example, xxxx-foo@your.domain will be treated
688# in the same way as xxxx@your.domain by this router. Because this router is
689# not used for verification, if you choose to uncomment those options, then you
690# will *need* to make the same change to the localuser router. (There are
691# other approaches, if this is undesirable, but they add complexity).
692
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693# The check_ancestor option means that if the forward file generates an
694# address that is an ancestor of the current one, the current one gets
695# passed on instead. This covers the case where A is aliased to B and B
696# has a .forward file pointing to A.
697
698# The three transports specified at the end are those that are used when
699# forwarding generates a direct delivery to a file, or to a pipe, or sets
700# up an auto-reply, respectively.
701
702userforward:
703 driver = redirect
704 check_local_user
705# local_part_suffix = +* : -*
706# local_part_suffix_optional
707 file = $home/.forward
708# allow_filter
709 no_verify
710 no_expn
711 check_ancestor
712 file_transport = address_file
713 pipe_transport = address_pipe
714 reply_transport = address_reply
715
716
717# This router matches local user mailboxes. If the router fails, the error
718# message is "Unknown user".
719
720# If you want this router to treat local parts with suffixes introduced by "-"
721# or "+" characters as if the suffixes did not exist, uncomment the two local_
722# part_suffix options. Then, for example, xxxx-foo@your.domain will be treated
723# in the same way as xxxx@your.domain by this router.
724
725localuser:
726 driver = accept
727 check_local_user
728# local_part_suffix = +* : -*
729# local_part_suffix_optional
730 transport = local_delivery
731 cannot_route_message = Unknown user
732
733
734
735######################################################################
736# TRANSPORTS CONFIGURATION #
737######################################################################
738# ORDER DOES NOT MATTER #
739# Only one appropriate transport is called for each delivery. #
740######################################################################
741
742# A transport is used only when referenced from a router that successfully
743# handles an address.
744
745begin transports
746
747
748# This transport is used for delivering messages over SMTP connections.
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749# Refuse to send any message with over-long lines, which could have
750# been received other than via SMTP. The use of message_size_limit to
8c952127 751# enforce this is a red herring.
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752
753remote_smtp:
754 driver = smtp
8c952127 755 message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
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756.ifdef _HAVE_DANE
757 dnssec_request_domains = *
758 hosts_try_dane = *
759.endif
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760
761
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762# This transport is used for delivering messages to a smarthost, if the
763# smarthost router is enabled. This starts from the same basis as
764# "remote_smtp" but then turns on various security options, because
765# we assume that if you're told "use smarthost.example.org as the smarthost"
766# then there will be TLS available, with a verifiable certificate for that
767# hostname, using decent TLS.
768
769smarthost_smtp:
770 driver = smtp
771 message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
772 multi_domain
773 #
774.ifdef _HAVE_TLS
775 # Comment out any of these which you have to, then file a Support
776 # request with your smarthost provider to get things fixed:
777 hosts_require_tls = *
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778 tls_verify_hosts = *
779 # As long as tls_verify_hosts is enabled, this won't matter, but if you
780 # have to comment it out then this will at least log whether you succeed
781 # or not:
782 tls_try_verify_hosts = *
783 #
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784 # The SNI name should match the name which we'll expect to verify;
785 # many mail systems don't use SNI and this doesn't matter, but if it does,
786 # we need to send a name which the remote site will recognize.
aa6e77af 787 # This _should_ be the name which the smarthost operators specified as
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788 # the hostname for sending your mail to.
789 tls_sni = ROUTER_SMARTHOST
790 #
26739076 791.ifdef _HAVE_OPENSSL
bdf9ce82 792 tls_require_ciphers = HIGH:!aNULL:@STRENGTH
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793.endif
794.ifdef _HAVE_GNUTLS
bdf9ce82 795 tls_require_ciphers = SECURE192:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1
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796.endif
797.endif
798
799
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800# This transport is used for local delivery to user mailboxes in traditional
801# BSD mailbox format. By default it will be run under the uid and gid of the
802# local user, and requires the sticky bit to be set on the /var/mail directory.
803# Some systems use the alternative approach of running mail deliveries under a
804# particular group instead of using the sticky bit. The commented options below
805# show how this can be done.
806
807local_delivery:
808 driver = appendfile
809 file = /var/mail/$local_part
810 delivery_date_add
811 envelope_to_add
812 return_path_add
813# group = mail
814# mode = 0660
815
816
817# This transport is used for handling pipe deliveries generated by alias or
818# .forward files. If the pipe generates any standard output, it is returned
819# to the sender of the message as a delivery error. Set return_fail_output
820# instead of return_output if you want this to happen only when the pipe fails
821# to complete normally. You can set different transports for aliases and
822# forwards if you want to - see the references to address_pipe in the routers
823# section above.
824
825address_pipe:
826 driver = pipe
827 return_output
828
829
830# This transport is used for handling deliveries directly to files that are
831# generated by aliasing or forwarding.
832
833address_file:
834 driver = appendfile
835 delivery_date_add
836 envelope_to_add
837 return_path_add
838
839
840# This transport is used for handling autoreplies generated by the filtering
841# option of the userforward router.
842
843address_reply:
844 driver = autoreply
845
846
847
848######################################################################
849# RETRY CONFIGURATION #
850######################################################################
851
852begin retry
853
854# This single retry rule applies to all domains and all errors. It specifies
855# retries every 15 minutes for 2 hours, then increasing retry intervals,
856# starting at 1 hour and increasing each time by a factor of 1.5, up to 16
857# hours, then retries every 6 hours until 4 days have passed since the first
858# failed delivery.
859
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860# WARNING: If you do not have any retry rules at all (this section of the
861# configuration is non-existent or empty), Exim will not do any retries of
862# messages that fail to get delivered at the first attempt. The effect will
863# be to treat temporary errors as permanent. Therefore, DO NOT remove this
864# retry rule unless you really don't want any retries.
865
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866# Address or Domain Error Retries
867# ----------------- ----- -------
868
869* * F,2h,15m; G,16h,1h,1.5; F,4d,6h
870
871
872
873######################################################################
874# REWRITE CONFIGURATION #
875######################################################################
876
877# There are no rewriting specifications in this default configuration file.
878
879begin rewrite
880
881
882
883######################################################################
884# AUTHENTICATION CONFIGURATION #
885######################################################################
886
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887# The following authenticators support plaintext username/password
888# authentication using the standard PLAIN mechanism and the traditional
889# but non-standard LOGIN mechanism, with Exim acting as the server.
890# PLAIN and LOGIN are enough to support most MUA software.
891#
892# These authenticators are not complete: you need to change the
893# server_condition settings to specify how passwords are verified.
894# They are set up to offer authentication to the client only if the
895# connection is encrypted with TLS, so you also need to add support
896# for TLS. See the global configuration options section at the start
897# of this file for more about TLS.
898#
899# The default RCPT ACL checks for successful authentication, and will accept
900# messages from authenticated users from anywhere on the Internet.
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901
902begin authenticators
903
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904# PLAIN authentication has no server prompts. The client sends its
905# credentials in one lump, containing an authorization ID (which we do not
906# use), an authentication ID, and a password. The latter two appear as
907# $auth2 and $auth3 in the configuration and should be checked against a
908# valid username and password. In a real configuration you would typically
909# use $auth2 as a lookup key, and compare $auth3 against the result of the
910# lookup, perhaps using the crypteq{}{} condition.
911
912#PLAIN:
913# driver = plaintext
914# server_set_id = $auth2
915# server_prompts = :
916# server_condition = Authentication is not yet configured
d9b2312b 917# server_advertise_condition = ${if def:tls_in_cipher }
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918
919# LOGIN authentication has traditional prompts and responses. There is no
920# authorization ID in this mechanism, so unlike PLAIN the username and
921# password are $auth1 and $auth2. Apart from that you can use the same
922# server_condition setting for both authenticators.
923
924#LOGIN:
925# driver = plaintext
926# server_set_id = $auth1
927# server_prompts = <| Username: | Password:
928# server_condition = Authentication is not yet configured
d9b2312b 929# server_advertise_condition = ${if def:tls_in_cipher }
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930
931
932######################################################################
933# CONFIGURATION FOR local_scan() #
934######################################################################
935
936# If you have built Exim to include a local_scan() function that contains
937# tables for private options, you can define those options here. Remember to
938# uncomment the "begin" line. It is commented by default because it provokes
939# an error with Exim binaries that are not built with LOCAL_SCAN_HAS_OPTIONS
940# set in the Local/Makefile.
941
942# begin local_scan
943
944
945# End of Exim configuration file