+# Below is an Exim 4 config file which is designed for an Exim server that
+# is put in front of an Exchange 5.5 system but which verifies the valid
+# addresses that are stored in Exchange via LDAP lookups against the Exchange
+# server. The advantage being that I can do much more aggressive spam
+# fighting, make my own set of policy decisions etc, using the flexibility of
+# Exim while still supporting the Exchange system for final delivery (not my
+# ideal situation but the company relies on it). In any case, I thought this
+# was sufficiently useful and answers some semi-regular questions on the list,
+# that it might be included in either the FAQ or the sample configs.
+
+# From: Tabor J. Wells <twells@fsckit.net>
+# Date: Wed, 21 Aug 2002 11:16:36 -0400
+
+
+
+
+######################################################################
+# Runtime configuration file for Exim #
+######################################################################
+
+
+# This is a default configuration file which will operate correctly in
+# uncomplicated installations. Please see the manual for a complete list
+# of all the runtime configuration options that can be included in a
+# 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.
+
+
+# This file is divided into several parts, all but the first of which are
+# headed by a line starting with the word "begin". Only those parts that
+# are required need to be present. Blank lines, and lines starting with #
+# are ignored.
+
+
+########### IMPORTANT ########## IMPORTANT ########### IMPORTANT ###########
+# #
+# Whenever you change Exim's configuration file, you *must* remember to #
+# HUP the Exim daemon, because it will not pick up the new configuration #
+# until you do. However, any other Exim processes that are started, for #
+# example, a process started by an MUA in order to send a message, will #
+# see the new configuration as soon as it is in place. #
+# #
+# You do not need to HUP the daemon for changes in auxiliary files that #
+# are referenced from this file. They are read every time they are used. #
+# #
+# It is usually a good idea to test a new configuration for syntactic #
+# correctness before installing it (for example, by running the command #
+# "exim -C /config/file.new -bV"). #
+# #
+########### IMPORTANT ########## IMPORTANT ########### IMPORTANT ###########
+
+
+
+######################################################################
+# 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
+# uname() function is called to obtain the name. In many cases this does
+# the right thing and you need not set anything explicitly.
+
+# primary_hostname =
+
+
+# The next three settings create two lists of domains and one list of hosts.
+# These lists are referred to later in this configuration using the syntax
+# +local_domains, +relay_to_domains, and +relay_from_hosts, respectively. They
+# are all colon-separated lists:
+
+domainlist local_domains = @ : dbm;/etc/exim/db/localdomains.db
+domainlist relay_to_domains =
+hostlist relay_from_hosts = 127.0.0.1 : 192.168.1.0/24
+
+# Most straightforward access control requirements can be obtained by
+# appropriate settings of the above options. In more complicated situations, you
+# may need to modify the Access Control List (ACL) which appears later in this
+# file.
+
+# The first setting specifies your local domains, for example:
+#
+# domainlist local_domains = my.first.domain : my.second.domain
+#
+# You can use "@" to mean "the name of the local host", as in the default
+# setting above. This is the name that is specified by primary_hostname,
+# as specified above (or defaulted). If you do not want to do any local
+# deliveries, remove the "@" from the setting above. If you want to accept mail
+# addressed to your host's literal IP address, for example, mail addressed to
+# "user@[192.168.23.44]", you can add "@[]" as an item in the local domains
+# list. You also need to uncomment "allow_domain_literals" below. This is not
+# recommended for today's Internet.
+
+# The second setting specifies domains for which your host is an incoming relay.
+# If you are not doing any relaying, you should leave the list empty. However,
+# if your host is an MX backup or gateway of some kind for some domains, you
+# must set relay_to_domains to match those domains. For example:
+#
+# domainlist relay_to_domains = *.myco.com : my.friend.org
+#
+# This will allow any host to relay through your host to those domains.
+# See the section of the manual entitled "Control of relaying" for more
+# information.
+
+# The third setting specifies hosts that can use your host as an outgoing relay
+# 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
+#
+# 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.
+
+
+# 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 list for
+# incoming messages. The name of this ACL is defined here:
+
+acl_smtp_rcpt = acl_check_rcpt
+
+# You should not change that setting until you understand how ACLs work.
+
+
+# Specify the domain you want to be added to all unqualified addresses
+# here. An unqualified address is one that does not contain an "@" character
+# followed by a domain. For example, "caesar@rome.example" is a fully qualified
+# address, but the string "caesar" (i.e. just a login name) is an unqualified
+# email address. Unqualified addresses are accepted only from local callers by
+# default. See the recipient_unqualified_hosts option if you want to permit
+# unqualified addresses from remote sources. If this option is not set, the
+# primary_hostname value is used for qualification.
+
+# qualify_domain =
+
+
+# If you want unqualified recipient addresses to be qualified with a different
+# domain to unqualified sender addresses, specify the recipient domain here.
+# If this option is not set, the qualify_domain value is used.
+
+# qualify_recipient =
+
+
+# The following line must be uncommented if you want Exim to recognize
+# addresses of the form "user@[10.11.12.13]" that is, with a "domain literal"
+# (an IP address) instead of a named domain. The RFCs still require this form,
+# but it makes little sense to permit mail to be sent to specific hosts by
+# their IP address in the modern Internet. This ancient format has been used
+# by those seeking to abuse hosts by using them for unwanted relaying. If you
+# really do want to support domain literals, uncomment the following line, and
+# see also the "domain_literal" router below.
+
+# allow_domain_literals
+
+
+# No deliveries will ever be run under the uids of these users (a colon-
+# separated list). An attempt to do so causes a panic error to be logged, and
+# the delivery to be deferred. This is a paranoic safety catch. Note that the
+# default setting means you cannot deliver mail addressed to root as if it
+# were a normal user. This isn't usually a problem, as most sites have an alias
+# for root that redirects such mail to a human administrator.
+
+never_users = root
+
+
+# The setting below causes Exim to do a reverse DNS lookup on all incoming
+# IP calls, in order to get the true host name. If you feel this is too
+# expensive, you can specify the networks for which a lookup is done, or
+# remove the setting entirely.
+
+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 an SMTP session.
+
+rfc1413_hosts = *
+rfc1413_query_timeout = 30s
+
+
+# By default, Exim expects all envelope addresses to be fully qualified, that
+# is, they must contain both a local part and a domain. If you want to accept
+# unqualified addresses (just a local part) from certain hosts, you can specify
+# these hosts by setting one or both of
+#
+# sender_unqualified_hosts =
+# recipient_unqualified_hosts =
+#
+# to control sender and recipient addresses, respectively. When this is done,
+# unqualified addresses are qualified using the settings of qualify_domain
+# and/or qualify_recipient (see above).
+
+
+# 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
+# the domains listed) is locally rerouted to x@y and sent on. If z is not one
+# of the "percent hack" domains, x%y is treated as an ordinary local part. This
+# hack is rarely needed nowadays; you should not enable it unless you are sure
+# that you really need it.
+#
+# percent_hack_domains =
+#
+# As well as setting this option you will also need to remove the test
+# for local parts containing % in the ACL definition below.
+
+
+# When Exim can neither deliver a message nor return it to sender, it "freezes"
+# the delivery error message (aka "bounce message"). There are also other
+# circumstances in which messages get frozen. They will stay on the queue for
+# ever unless one of the following options is set.
+
+# This option unfreezes frozen bounce messages after two days, tries
+# once more to deliver them, and ignores any delivery failures.
+
+ignore_bounce_errors_after = 2d
+
+# This option cancels (removes) frozen messages that are older than a week.
+
+timeout_frozen_after = 7d
+
+# Defined LDAP default servers
+ldap_default_servers = 192.168.1.101
+
+
+
+######################################################################
+# ACL CONFIGURATION #
+# Specifies access control lists for incoming SMTP mail #
+######################################################################
+
+begin acl
+
+# This access control list is used for every RCPT command in an incoming
+# SMTP message. The tests are run in order until the address is either
+# accepted or denied.
+
+acl_check_rcpt:
+
+ # Accept if the source is local SMTP (i.e. not over TCP/IP). We do this by
+ # testing for an empty sending host field.
+
+ accept hosts = :
+
+ # Deny if the local part contains @ or % or / or | or !. These are rarely
+ # found in genuine local parts, but are often tried by people looking to
+ # circumvent relaying restrictions.
+
+ # Also deny if the local part starts with a dot. Empty components aren't
+ # strictly legal in RFC 2822, but Exim allows them because this is common.
+ # However, actually starting with a dot may cause trouble if the local part
+ # is used as a file name (e.g. for a mailing list).
+
+ deny local_parts = ^.*[@%!/|] : ^\\.
+
+ # Accept mail to postmaster in any local domain, regardless of the source,
+ # and without verifying the sender.
+
+ accept local_parts = postmaster
+ domains = +local_domains
+
+ # Deny unless the sender address can be verified.
+
+ require verify = sender
+
+ #############################################################################
+ # There are no checks on DNS "black" lists because the domains that contain
+ # these lists are changing all the time. However, here are two examples of
+ # how you could get Exim to perform a DNS black list lookup at this point.
+ # The first one denies, while 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
+ #
+ # warn message = X-Warning: $sender_host_address is in a black list at $dnslist_domain
+ # log_message = found in $dnslist_domain
+ # dnslists = black.list.example
+ #############################################################################
+
+ # Accept if the address is in a local domain, but only if the recipient can
+ # be verified. Otherwise deny. The "endpass" line is the border between
+ # passing on to the next ACL statement (if tests above it fail) or denying
+ # access (if tests below it fail).
+
+ accept domains = +local_domains
+ endpass
+ message = unknown user
+ verify = recipient
+
+ # Accept if the address is in a domain for which we are relaying, but again,
+ # only if the recipient can be verified.
+
+ accept domains = +relay_to_domains
+ endpass
+ message = unrouteable address
+ verify = recipient
+
+ # If control reaches this point, the domain is neither in +local_domains
+ # nor in +relay_to_domains.
+
+ # Accept if the message comes from one of the hosts for which we are an
+ # outgoing relay. Recipient verification is omitted here, because in many
+ # cases the clients are dumb MUAs that don't cope well with SMTP error
+ # responses. If you are actually relaying out from MTAs, you should probably
+ # add recipient verification here.
+
+ accept hosts = +relay_from_hosts
+
+ # Accept if the message arrived over an authenticated connection, from
+ # any host. Again, these messages are usually from MUAs, so recipient
+ # verification is omitted.
+
+ accept authenticated = *
+
+ # Reaching the end of the ACL causes a "deny", but we might as well give
+ # an explicit message.
+
+ deny message = relay not permitted
+
+
+
+######################################################################
+# ROUTERS CONFIGURATION #
+# Specifies how addresses are handled #
+######################################################################
+# THE ORDER IN WHICH THE ROUTERS ARE DEFINED IS IMPORTANT! #
+# An address is passed to each router in turn until it is accepted. #
+######################################################################
+
+begin routers
+
+# This router routes to remote hosts over SMTP by explicit IP address,
+# when an email address is given in "domain literal" form, for example,
+# <user@[192.168.35.64]>. The RFCs require this facility. However, it is
+# little-known these days, and has been exploited by evil people seeking
+# to abuse SMTP relays. Consequently it is commented out in the default
+# configuration. If you uncomment this router, you also need to uncomment
+# allow_domain_literals above, so that Exim can recognize the syntax of
+# domain literal addresses.
+
+# domain_literal:
+# driver = ipliteral
+# domains = ! +local_domains
+# transport = remote_smtp
+
+
+# This router routes addresses that are not in local domains by doing a DNS
+# lookup on the domain name. Any domain that resolves to 0.0.0.0 or to a
+# loopback interface address (127.0.0.0/8) is treated as if it had no DNS
+# entry. Note that 0.0.0.0 is the same as 0.0.0.0/32, which is commonly treated
+# as the local host inside the network stack. It is not 0.0.0.0/0, the default
+# route. If the DNS lookup fails, no further routers are tried because of
+# the no_more setting, and consequently the address is unrouteable.
+
+dnslookup:
+ driver = dnslookup
+ domains = ! +local_domains
+ transport = remote_smtp
+ ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8 : 10.0.0.0/8 : 172.16.0.0/12
+ no_more
+
+
+# The remaining routers handle addresses in the local domain(s).
+
+
+# This router handles aliasing using a traditional /etc/aliases file.
+#
+##### NB You must ensure that /etc/aliases exists. It used to be the case
+##### NB that every Unix had that file, because it was the Sendmail default.
+##### NB These days, there are systems that don't have it. Your aliases
+##### NB file should at least contain an alias for "postmaster".
+#
+# If any of your aliases expand to pipes or files, you will need to set
+# up a user and a group for these deliveries to run under. You can do
+# this by uncommenting the "user" option below (changing the user name
+# as appropriate) and adding a "group" option if necessary. Alternatively, you
+# can specify "user" on the transports that are used. Note that the transports
+# listed below are the same as are used for .forward files; you might want
+# to set up different ones for pipe and file deliveries from aliases.
+
+system_aliases:
+ driver = redirect
+ allow_fail
+ allow_defer
+ data = ${lookup{$local_part}lsearch{/etc/exim/txt/aliases.txt}}
+# user = exim
+ file_transport = address_file
+ pipe_transport = address_pipe
+
+# This router matches local user mailboxes.
+# Domains set to $primary_hostname so that I can route stuff locally as need
+# be but prevent user@mylocaldomain.com from delivering locally when 'user'
+# also matches the Exchange lookup below.
+
+localuser:
+ driver = accept
+ check_local_user
+ domains = $primary_hostname
+ transport = local_delivery
+ no_more
+
+# Routers for lookups in LDAP on Exchange if they exist there then punt
+
+# First if it exists as a otherMailbox=smtp$user@example.com (Exchange's
+# format for aliases then substitute the canonical email address for this user
+# as defined by mail=
+
+exchangeothermailboxlookup:
+ driver = redirect
+ data = ${lookup ldap {ldap:///?mail?sub?(otherMailbox=smtp\$${quote_ldap:$local_part}@${quote_ldap:$domain})}}
+ domains = dbm;/etc/exim/db/localdomains.db
+ verify_recipient
+
+# This lookup verifies the mail=user@example.com format and if it exists
+# Pass to the the manualroute router which is used to punt to the internal
+# Exchange server as defined by domain.
+
+exchangemaillookup:
+ driver = redirect
+ data = ${lookup ldap {ldap:///?mail?sub?(mail=${quote_ldap:$local_part}@${quote_ldap:$domain})}}
+ domains = dbm;/etc/exim/db/localdomains.db
+ verify_recipient
+ self = pass
+ pass_router = exchangeroute
+ no_more
+
+# localdomains.db contain entries that look like:
+# example.com: 192.168.1.101
+# example.net: 192.168.1.102
+# etc.
+
+exchangeroute:
+ driver = manualroute
+ transport = remote_smtp
+ route_data = ${lookup{$domain}dbm{/etc/exim/db/localdomains.db}}
+
+######################################################################
+# TRANSPORTS CONFIGURATION #
+######################################################################
+# ORDER DOES NOT MATTER #
+# Only one appropriate transport is called for each delivery. #
+######################################################################
+
+# A transport is used only when referenced from a router that successfully
+# handles an address.
+
+begin transports
+
+
+# This transport is used for delivering messages over SMTP connections.
+
+remote_smtp:
+ driver = smtp
+
+
+# This transport is used for local delivery to user mailboxes in traditional
+# BSD mailbox format. By default it will be run under the uid and gid of the
+# local user, and requires the sticky bit to be set on the /var/mail directory.
+# Some systems use the alternative approach of running mail deliveries under a
+# particular group instead of using the sticky bit. The commented options below
+# show how this can be done.
+
+local_delivery:
+ driver = appendfile
+ file = /var/mail/$local_part
+ delivery_date_add
+ envelope_to_add
+ return_path_add
+# group = mail
+# mode = 0660
+
+
+# This transport is used for handling pipe deliveries generated by alias or
+# .forward files. If the pipe generates any standard output, it is returned
+# to the sender of the message as a delivery error. Set return_fail_output
+# instead of return_output if you want this to happen only when the pipe fails
+# to complete normally. You can set different transports for aliases and
+# forwards if you want to - see the references to address_pipe in the routers
+# section above.
+
+address_pipe:
+ driver = pipe
+ return_output
+
+
+# This transport is used for handling deliveries directly to files that are
+# generated by aliasing or forwarding.
+
+address_file:
+ driver = appendfile
+ delivery_date_add
+ envelope_to_add
+ return_path_add
+
+
+# This transport is used for handling autoreplies generated by the filtering
+# option of the userforward router.
+
+address_reply:
+ driver = autoreply
+
+
+
+######################################################################
+# RETRY CONFIGURATION #
+######################################################################
+
+begin retry
+
+# This single retry rule applies to all domains and all errors. It specifies
+# retries every 15 minutes for 2 hours, then increasing retry intervals,
+# starting at 1 hour and increasing each time by a factor of 1.5, up to 16
+# hours, then retries every 6 hours until 4 days have passed since the first
+# failed delivery.
+
+# Domain Error Retries
+# ------ ----- -------
+
+* * F,2h,15m; G,16h,1h,1.5; F,4d,6h
+
+
+
+######################################################################
+# REWRITE CONFIGURATION #
+######################################################################
+
+# There are no rewriting specifications in this default configuration file.
+
+begin rewrite
+
+
+
+######################################################################
+# AUTHENTICATION CONFIGURATION #
+######################################################################
+
+# There are no authenticator specifications in this default configuration file.
+
+begin authenticators
+
+
+# End of Exim configuration file