X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/ff284120aa17a2b2d16d13bcdf67b794800f047c..2c47372fad0f829ddfa29d04095f57a70206469c:/src/src/configure.default

diff --git a/src/src/configure.default b/src/src/configure.default
index 12743499c..79bbc8c30 100644
--- a/src/src/configure.default
+++ b/src/src/configure.default
@@ -40,6 +40,7 @@
 ######################################################################
 #                    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
@@ -152,6 +153,9 @@ acl_smtp_data = acl_check_data
 # 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.
@@ -221,18 +225,26 @@ never_users = root
 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 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
 
-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
@@ -248,6 +260,13 @@ rfc1413_query_timeout = 5s
 # 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
@@ -314,6 +333,18 @@ timeout_frozen_after = 7d
 # 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      #
@@ -421,6 +452,11 @@ acl_check_rcpt:
           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.
@@ -477,6 +513,19 @@ acl_check_rcpt:
 
 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.
   #
@@ -669,9 +718,13 @@ begin transports
 
 
 # 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}}
 
 
 # This transport is used for local delivery to user mailboxes in traditional