1 = Mail Transfer Agents = 2 3 Although this documentation does not seek to cover the details of configuring 4 mail transfer agent (MTA) software, some hints and tips are offered to help 5 avoid frustration. 6 7 == General == 8 9 Some general measures are presented below. 10 11 === Mailname === 12 13 The contents of `/etc/mailname` should probably be the fully-qualified hostname, 14 at least for Exim and Postfix. See 15 [[https://wiki.debian.org/EtcMailName|the Debian Wiki page]] for more details. 16 17 === Hostname === 18 19 The `hostname` command should provide a suitable hostname on the system, or MTAs 20 may behave strangely. This can be tested with the following command: 21 22 {{{ 23 hostname -f 24 }}} 25 26 It should report a fully-qualified hostname. 27 28 === Interfaces === 29 30 Some software attempts to listen on interfaces that may not be supported. For example, 31 Exim may be configured to listen on both IPv4 and IPv6 interfaces, even in environments 32 (such as User Mode Linux) where IPv6 interfaces may not be available. 33 34 == Exim == 35 36 On Debian, the following command can be run to adjust the configuration: 37 38 {{{ 39 dpkg-reconfigure exim4-config 40 }}} 41 42 The following questions are especially interesting: 43 44 {{{{#!table 45 '''Question''' || '''Remarks''' 46 == 47 IP-addresses to listen on for incoming SMTP connections 48 || Remove IPv6 interfaces in User Mode Linux or other environments without 49 .. IPv6 support or Exim will not bother listening on IPv4 interfaces either. 50 == 51 System mail name 52 || State the fully-qualified hostname, not just the domain name, which is 53 .. what the dialogue suggests is sufficient. For example: 54 {{{ 55 mailserver.example.com 56 }}} 57 == 58 Other destinations for which mail is accepted 59 || This is a colon-separated list that should indicate the local domain as 60 .. well as the unqualified hostname. For example: 61 {{{ 62 mailserver:example.com 63 }}} 64 }}}}