######################################################################
# 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
# tls_certificate = /etc/ssl/exim.crt
# tls_privatekey = /etc/ssl/exim.pem
+# For OpenSSL, prefer EC- over RSA-authenticated ciphers
+# tls_require_ciphers = ECDSA:RSA:!COMPLEMENTOFDEFAULT
+
# 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.
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.
+#
+prdr_enable = true
# 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
# 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 #
control = submission
control = dkim_disable_verify
+ # Insist that a HELO/EHLO was accepted.
+
+ require message = nice hosts say HELO first
+ condition = ${if def:sender_helo_name}
+
# Insist that any other recipient address that we accept is either in one of
# our local domains, or is in a domain for which we explicitly allow
# relaying. Any other domain is rejected as being unacceptable for relaying.
acl_check_data:
+ # Deny if the message contains an overlong line. Per the standards
+ # we should never receive one such via SMTP.
+ #
+ deny message = maximum allowed line length is 998 octets, \
+ got $max_received_linelength
+ condition = ${if > {$max_received_linelength}{998}}
+
+ # 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.
#
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
+ dnssec_request_domains = *
no_more
+# This alternative 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. If you uncomment "smarthost" then you
+# should comment out "dnslookup" above. Setting a real hostname in route_data
+# wouldn't hurt either.
+
+# smarthost:
+# driver = manualroute
+# domains = ! +local_domains
+# transport = smarthost_smtp
+# route_data = MAIL.HOSTNAME.FOR.CENTRAL.SERVER.EXAMPLE
+# ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
+# no_more
+
+
# 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
# This transport is used for delivering messages over SMTP connections.
+# Refuse to send any message with over-long lines, which could have
+# been received other than via SMTP. The use of message_size_limit to
+# enforce this is a red herring.
remote_smtp:
driver = smtp
+ message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
+.ifdef _HAVE_DANE
+ dnssec_request_domains = *
+ hosts_try_dane = *
+.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
+ message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
+ 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_sni = $host
+ tls_verify_hosts = *
+ # As long as tls_verify_hosts is enabled, this won't matter, but if you
+ # have to comment it out then this will at least log whether you succeed
+ # or not:
+ tls_try_verify_hosts = *
+ #
+.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
+.endif
# This transport is used for local delivery to user mailboxes in traditional
# 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