-# $Cambridge: exim/src/src/configure.default,v 1.15 2010/06/03 08:19:13 pdp Exp $
-
######################################################################
# Runtime configuration file for Exim #
######################################################################
# configuration file. There are many more than are mentioned here. The
# manual is in the file doc/spec.txt in the Exim distribution as a plain
# ASCII file. Other formats (PostScript, Texinfo, HTML, PDF) are available
-# from the Exim ftp sites. The manual is also online at the Exim web sites.
+# from the Exim ftp sites. The manual is also online at the Exim website.
# This file is divided into several parts, all but the first of which are
+######################################################################
+# MACROS #
+######################################################################
+#
+
+# If you want to use a smarthost instead of sending directly to recipient
+# domains, uncomment this macro definition and set a real hostname.
+# An appropriately privileged user can then redirect email on the command-line
+# in emergencies, via -D.
+#
+# ROUTER_SMARTHOST=MAIL.HOSTNAME.FOR.CENTRAL.SERVER.EXAMPLE
+
######################################################################
# MAIN CONFIGURATION SETTINGS #
######################################################################
+#
# Specify your host's canonical name here. This should normally be the fully
# qualified "official" name of your host. If this option is not set, the
domainlist local_domains = @
domainlist relay_to_domains =
-hostlist relay_from_hosts = 127.0.0.1
+hostlist relay_from_hosts = localhost
+# (We rely upon hostname resolution working for localhost, because the default
+# uncommented configuration needs to work in IPv4-only environments.)
# Most straightforward access control requirements can be obtained by
# appropriate settings of the above options. In more complicated situations,
# to any other host on the Internet. Such a setting commonly refers to a
# complete local network as well as the localhost. For example:
#
-# hostlist relay_from_hosts = 127.0.0.1 : 192.168.0.0/16
+# hostlist relay_from_hosts = <; 127.0.0.1 ; ::1 ; 192.168.0.0/16
#
# The "/16" is a bit mask (CIDR notation), not a number of hosts. Note that you
# have to include 127.0.0.1 if you want to allow processes on your host to send
# SMTP mail by using the loopback address. A number of MUAs use this method of
-# sending mail.
+# sending mail. Often, connections are made to "localhost", which might be ::1
+# on IPv6-enabled hosts. Do not forget CIDR for your IPv6 networks.
# All three of these lists may contain many different kinds of item, including
# wildcarded names, regular expressions, and file lookups. See the reference
# manual for details. The lists above are used in the access control lists for
# checking incoming messages. The names of these ACLs are defined here:
-acl_smtp_rcpt = acl_check_rcpt
-acl_smtp_data = acl_check_data
+acl_smtp_rcpt = acl_check_rcpt
+.ifdef _HAVE_PRDR
+acl_smtp_data_prdr = acl_check_prdr
+.endif
+acl_smtp_data = acl_check_data
# You should not change those settings until you understand how ACLs work.
# spamd_address = 127.0.0.1 783
-# If Exim is compiled with support for TLS, you may want to enable the
-# following options so that Exim allows clients to make encrypted
-# connections. In the authenticators section below, there are template
-# configurations for plaintext username/password authentication. This kind
-# of authentication is only safe when used within a TLS connection, so the
-# authenticators will only work if the following TLS settings are turned on
-# as well.
+# If Exim is compiled with support for TLS, you may want to change the
+# following option so that Exim disallows certain clients from makeing encrypted
+# connections. The default is to allow all.
+# In the authenticators section below, there are template configurations for
+# plaintext username/password authentication. This kind of authentication is
+# only safe when used within a TLS connection, so the authenticators will only
+# work if TLS is allowed here.
-# Allow any client to use TLS.
+# This is equivalent to the default.
# tls_advertise_hosts = *
# tls_certificate = /etc/ssl/exim.crt
# tls_privatekey = /etc/ssl/exim.pem
+# For OpenSSL, prefer EC- over RSA-authenticated ciphers
+.ifdef _HAVE_OPENSSL
+tls_require_ciphers = ECDSA:RSA:!COMPLEMENTOFDEFAULT
+.endif
+
+# Don't offer resumption to (most) MUAs, who we don't want to reuse
+# tickets. Once the TLS extension for vended ticket numbers comes
+# though, re-examine since resumption on a single-use ticket is still a benefit.
+.ifdef _HAVE_TLS_RESUME
+tls_resumption_hosts = ${if inlist {$received_port}{587:465} {:}{*}}
+.endif
+
# In order to support roaming users who wish to send email from anywhere,
# you may want to make Exim listen on other ports as well as port 25, in
# case these users need to send email from a network that blocks port 25.
-# The standard port for this purpose is port 587, the "message submission"
-# port. See RFC 4409 for details. Microsoft MUAs cannot be configured to
+# The standard ports for this purpose are:
+# port 587, the "message submission" port - see RFC 4409 for details,
+# and 465 the TLS-encrypted "submission" port, service name is "submissions",
+# see RFC 8314.
+
+# Microsoft MUAs cannot be configured to
# talk the message submission protocol correctly, so if you need to support
-# them you should also allow TLS-on-connect on the traditional but
-# non-standard port 465.
+# them you should also allow TLS-on-connect on the traditional (and now
+# standard) port 465.
# daemon_smtp_ports = 25 : 465 : 587
# tls_on_connect_ports = 465
host_lookup = *
-# The settings below, which are actually the same as the defaults in the
-# code, cause Exim to make RFC 1413 (ident) callbacks for all incoming SMTP
-# calls. You can limit the hosts to which these calls are made, and/or change
-# the timeout that is used. If you set the timeout to zero, all RFC 1413 calls
-# are disabled. RFC 1413 calls are cheap and can provide useful information
-# for tracing problem messages, but some hosts and firewalls have problems
-# with them. This can result in a timeout instead of an immediate refused
-# connection, leading to delays on starting up SMTP sessions. (The default was
-# reduced from 30s to 5s for release 4.61.)
+# The setting below causes Exim to try to initialize the system resolver
+# library with DNSSEC support. It has no effect if your library lacks
+# DNSSEC support.
+
+dns_dnssec_ok = 1
-rfc1413_hosts = *
-rfc1413_query_timeout = 5s
+
+# The settings below cause Exim to make RFC 1413 (ident) callbacks
+# for all incoming SMTP calls. You can limit the hosts to which these
+# calls are made, and/or change the timeout that is used. If you set
+# the timeout to zero, all RFC 1413 calls are disabled. RFC 1413 calls
+# are cheap and can provide useful information for tracing problem
+# messages, but some hosts and firewalls have problems with them.
+# This can result in a timeout instead of an immediate refused
+# connection, leading to delays on starting up SMTP sessions.
+# (The default was reduced from 30s to 5s for release 4.61. and to
+# disabled for release 4.86)
+#
+#rfc1413_hosts = *
+#rfc1413_query_timeout = 5s
+
+
+# Enable an efficiency feature. We advertise the feature; clients
+# may request to use it. For multi-recipient mails we then can
+# reject or accept per-user after the message is received.
+# This supports recipient-dependent content filtering; without it
+# you have to temp-reject any recipients after the first that have
+# incompatible filtering, and do the filtering in the data ACL.
+# Even with this enabled, you must support the old style for peers
+# not flagging support for PRDR (visible via $prdr_requested).
+#
+.ifdef _HAVE_PRDR
+prdr_enable = true
+.endif
# By default, Exim expects all envelope addresses to be fully qualified, that
# and/or qualify_recipient (see above).
+# Unless you run a high-volume site you probably want more logging
+# detail than the default. Adjust to suit.
+
+log_selector = +smtp_protocol_error +smtp_syntax_error \
+ +tls_certificate_verified
+
+
# If you want Exim to support the "percent hack" for certain domains,
# uncomment the following line and provide a list of domains. The "percent
# hack" is the feature by which mail addressed to x%y@z (where z is one of
# By default, messages that are waiting on Exim's queue are all held in a
-# single directory called "input" which it itself within Exim's spool
+# single directory called "input" which is itself within Exim's spool
# directory. (The default spool directory is specified when Exim is built, and
# is often /var/spool/exim/.) Exim works best when its queue is kept short, but
# there are circumstances where this is not always possible. If you uncomment
# because of some popular, yet buggy, mail composition software.
+# If you wish to be strictly RFC compliant, or if you know you'll be
+# exchanging email with systems that are not 8-bit clean, then you may
+# wish to disable advertising 8BITMIME. Uncomment this option to do so.
+
+# accept_8bitmime = false
+
+
+# Exim does not make use of environment variables itself. However,
+# libraries that Exim uses (e.g. LDAP) depend on specific environment settings.
+# There are two lists: keep_environment for the variables we trust, and
+# add_environment for variables we want to set to a specific value.
+# Note that TZ is handled separately by the timezone runtime option
+# and TIMEZONE_DEFAULT buildtime option.
+
+# keep_environment = ^LDAP
+# add_environment = PATH=/usr/bin::/bin
+
+
+
######################################################################
# ACL CONFIGURATION #
# Specifies access control lists for incoming SMTP mail #
require verify = sender
+ # Reject all RCPT commands after too many bad recipients
+ # This is partly a defense against spam abuse and partly attacker abuse.
+ # Real senders should manage, by the time they get to 10 RCPT directives,
+ # to have had at least half of them be real addresses.
+ #
+ # This is a lightweight check and can protect you against repeated
+ # invocations of more heavy-weight checks which would come after it.
+
+ deny condition = ${if and {\
+ {>{$rcpt_count}{10}}\
+ {<{$recipients_count}{${eval:$rcpt_count/2}}} }}
+ message = Rejected for too many bad recipients
+ logwrite = REJECT [$sender_host_address]: bad recipient count high [${eval:$rcpt_count-$recipients_count}]
+
# Accept if the message comes from one of the hosts for which we are an
# outgoing relay. It is assumed that such hosts are most likely to be MUAs,
# so we set control=submission to make Exim treat the message as a
# examples of how you can get Exim to perform a DNS black list lookup at this
# point. The first one denies, whereas the second just warns.
#
- # deny message = rejected because $sender_host_address is in a black list at $dnslist_domain\n$dnslist_text
- # dnslists = black.list.example
+ # deny dnslists = black.list.example
+ # message = rejected because $sender_host_address is in a black list at $dnslist_domain\n$dnslist_text
#
# warn dnslists = black.list.example
# add_header = X-Warning: $sender_host_address is in a black list at $dnslist_domain
# require verify = csa
#############################################################################
+ #############################################################################
+ # If doing per-user content filtering then recipients with filters different
+ # to the first recipient must be deferred unless the sender talks PRDR.
+ #
+ # defer !condition = $prdr_requested
+ # condition = ${if > {0}{$recipients_count}}
+ # condition = ${if !eq {$acl_m_content_filter} \
+ # {${lookup PER_RCPT_CONTENT_FILTER}}}
+ # warn !condition = $prdr_requested
+ # condition = ${if > {0}{$recipients_count}}
+ # set acl_m_content_filter = ${lookup PER_RCPT_CONTENT_FILTER}
+ #############################################################################
+
# At this point, the address has passed all the checks that have been
# configured, so we accept it unconditionally.
accept
+# This ACL is used once per recipient, for multi-recipient messages, if
+# we advertised PRDR. It can be used to perform receipient-dependent
+# header- and body- based filtering and rejections.
+# We set a variable to record that PRDR was active used, so that checking
+# in the data ACL can be skipped.
+
+.ifdef _HAVE_PRDR
+acl_check_prdr:
+ warn set acl_m_did_prdr = y
+
+ #############################################################################
+ # do lookup on filtering, with $local_part@$domain, deny on filter match
+ #
+ # deny set acl_m_content_filter = ${lookup PER_RCPT_CONTENT_FILTER}
+ # condition = ...
+ #############################################################################
+
+ accept
+.endif
+
# This ACL is used after the contents of a message have been received. This
# is the ACL in which you can test a message's headers or body, and in
# particular, this is where you can invoke external virus or spam scanners.
acl_check_data:
+ # Deny if the message contains an overlong line. Per the standards
+ # we should never receive one such via SMTP.
+ #
+ deny condition = ${if > {$max_received_linelength}{998}}
+ message = maximum allowed line length is 998 octets, \
+ got $max_received_linelength
+
+ # Deny if the headers contain badly-formed addresses.
+ #
+ deny !verify = header_syntax
+ message = header syntax
+ log_message = header syntax ($acl_verify_message)
+
# Deny if the message contains a virus. Before enabling this check, you
# must install a virus scanner and set the av_scanner option above.
#
# X-Spam_bar: $spam_bar\n\
# X-Spam_report: $spam_report
+ #############################################################################
+ # No more tests if PRDR was actively used.
+ # accept condition = ${if def:acl_m_did_prdr}
+ #
+ # To get here, all message recipients must have identical per-user
+ # content filtering (enforced by RCPT ACL). Do lookup for filter
+ # and deny on match.
+ #
+ # deny set acl_m_content_filter = ${lookup PER_RCPT_CONTENT_FILTER}
+ # condition = ...
+ #############################################################################
+
+
# Accept the message.
accept
# transport = remote_smtp
+# This router can be used when you want to send all mail to a
+# server which handles DNS lookups for you; an ISP will typically run such
+# a server for their customers. The hostname in route_data comes from the
+# macro defined at the top of the file. If not defined, then we'll use the
+# dnslookup router below instead.
+# Beware that the hostname is specified again in the Transport.
+
+.ifdef ROUTER_SMARTHOST
+
+smarthost:
+ driver = manualroute
+ domains = ! +local_domains
+ transport = smarthost_smtp
+ route_data = ROUTER_SMARTHOST
+ ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
+ no_more
+
+.else
+
# This router routes addresses that are not in local domains by doing a DNS
# lookup on the domain name. The exclamation mark that appears in "domains = !
# +local_domains" is a negating operator, that is, it can be read as "not". The
domains = ! +local_domains
transport = remote_smtp
ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
+# if ipv6-enabled then instead use:
+# ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
no_more
+# This closes the ROUTER_SMARTHOST ifdef around the choice of routing for
+# off-site mail.
+.endif
+
# The remaining routers handle addresses in the local domain(s), that is those
# domains that are defined by "domainlist local_domains" above.
# file starts with the string "# Exim filter" or "# Sieve filter", uncomment
# the "allow_filter" option.
-# If you want this router to treat local parts with suffixes introduced by "-"
-# or "+" characters as if the suffixes did not exist, uncomment the two local_
-# part_suffix options. Then, for example, xxxx-foo@your.domain will be treated
-# in the same way as xxxx@your.domain by this router. You probably want to make
-# the same change to the localuser router.
-
# The no_verify setting means that this router is skipped when Exim is
# verifying addresses. Similarly, no_expn means that this router is skipped if
# Exim is processing an EXPN command.
+# If you want this router to treat local parts with suffixes introduced by "-"
+# or "+" characters as if the suffixes did not exist, uncomment the two local_
+# part_suffix options. Then, for example, xxxx-foo@your.domain will be treated
+# in the same way as xxxx@your.domain by this router. Because this router is
+# not used for verification, if you choose to uncomment those options, then you
+# will *need* to make the same change to the localuser router. (There are
+# other approaches, if this is undesirable, but they add complexity).
+
# The check_ancestor option means that if the forward file generates an
# address that is an ancestor of the current one, the current one gets
# passed on instead. This covers the case where A is aliased to B and B
remote_smtp:
driver = smtp
+.ifdef _HAVE_TLS_RESUME
+ tls_resumption_hosts = *
+.endif
+
+
+# This transport is used for delivering messages to a smarthost, if the
+# smarthost router is enabled. This starts from the same basis as
+# "remote_smtp" but then turns on various security options, because
+# we assume that if you're told "use smarthost.example.org as the smarthost"
+# then there will be TLS available, with a verifiable certificate for that
+# hostname, using decent TLS.
+
+smarthost_smtp:
+ driver = smtp
+ multi_domain
+ #
+.ifdef _HAVE_TLS
+ # Comment out any of these which you have to, then file a Support
+ # request with your smarthost provider to get things fixed:
+ hosts_require_tls = *
+ tls_verify_hosts = *
+ # As long as tls_verify_hosts is enabled this will have no effect,
+ # but if you have to comment it out then this will at least log whether
+ # you succeed or not:
+ tls_try_verify_hosts = *
+ #
+ # The SNI name should match the name which we'll expect to verify;
+ # many mail systems don't use SNI and this doesn't matter, but if it does,
+ # we need to send a name which the remote site will recognize.
+ # This _should_ be the name which the smarthost operators specified as
+ # the hostname for sending your mail to.
+ tls_sni = ROUTER_SMARTHOST
+ #
+.ifdef _HAVE_OPENSSL
+ tls_require_ciphers = HIGH:!aNULL:@STRENGTH
+.endif
+.ifdef _HAVE_GNUTLS
+ tls_require_ciphers = SECURE192:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1
+.endif
+.ifdef _HAVE_TLS_RESUME
+ tls_resumption_hosts = *
+.endif
+.endif
# This transport is used for local delivery to user mailboxes in traditional
local_delivery:
driver = appendfile
- file = /var/mail/$local_part
+ file = /var/mail/$local_part_data
delivery_date_add
envelope_to_add
return_path_add
# server_set_id = $auth2
# server_prompts = :
# server_condition = Authentication is not yet configured
-# server_advertise_condition = ${if def:tls_cipher }
+# server_advertise_condition = ${if def:tls_in_cipher }
# LOGIN authentication has traditional prompts and responses. There is no
# authorization ID in this mechanism, so unlike PLAIN the username and
# server_set_id = $auth1
# server_prompts = <| Username: | Password:
# server_condition = Authentication is not yet configured
-# server_advertise_condition = ${if def:tls_cipher }
+# server_advertise_condition = ${if def:tls_in_cipher }
######################################################################
git://git.exim.org / exim.git / blobdiff