Mailman, in its default configuration, readily integrates with a properly-configured sendmail installation.
The discussion below gives specific file locations for a Solaris 9 installation. Solaris 10 locates the sendmail control file sources in /etc/mail/cf rather than /usr/lib/mail/cf. Locations of the sendmail executable and ancillary files are compile-time options for sendmail, so you will need to determine file locations for your specific installation. In our discussion, we also assume that the sendmail MTA that communicates with the Internet backbone and Mailman are installed on the same node (same hardware box).
Steps required for a Mailman-sendmail integration:
- Enable smrsh. Creating the directory links was covered in the previous installation step. In addition, assure that the link to the smrsh program is declared in main.mc. (/usr/lib/mail/cf/main.mc on a Solaris 9 system).
FEATURE(smrsh, /usr/lib/smrsh)dnl
For each list that you create, you need to add a set of alias pipes to the aliases file (typically /etc/mail/aliases) and run the newaliases program (/usr/sbin/newaliases). If you are following this guide for an initial Mailman installation, you will not be creating lists until later steps. Mailman will give you the alias information when you create a list. Additionaly, the $(prefix)/bin/genaliases script will generate all of aliases needed for all lists that have been created to stdout. These are in the correct format for the sendmail aliases file.
Set up sendmail masquerading to correspond to the Mailman configuration. For example, if your installation is on a machine known as myhost.mydomain.net and you create a list to receive mail at mylist@mydomain.net, you will need to masquerade as mydomain.net. You will also need to masquerade the sending envelope as well.
In its simplest form, the statements in main.mc for doing this are:
MASQUERADE_AS(mydomain.net')dnl FEATURE(masquerade_envelope')dnl
- Add the masquerade address to /etc/mail/local-host-names. For the example above, the local-host-names file must have:
mydomain.net
The above four items cover the basics needed to integrate Mailman with a simple sendmail installation. Except for the need to enable smrsh and to install piping aliases, virtually everything surrounding a Mailman installation supported by the sendmail MTA is specific to sendmail, and some of the above is abstracted from sendmail documentation.
This documentation includes:
The README included in the sendmail source distribution from http://www.sendmail.org/
Costales, Bryan: "Sendmail," 3rd edition, O'Reilly, 2002 This is commonly referred to as the "bat book."
Costales, Bryan: "Sendmail 8.13 Companion," O'Reilly, 2006
Additional resources are the web site and sendmail faq at: http://www.sendmail.org/ Usenet newsgroup comp.mail.sendmail
For convenience, we include comments here on sendmail configuration
considerations that often come up on the mailman-users list.
References are to Costales, "Sendmail".
A general guiding principle when working with sendmail is to "keep it simple." In particular, configure and test your sendmail installation thoroughly, with user accounts running simple MUA's such as elm or mutt, before expecting sendmail to work with Mailman. Virtually all of the problems users encounter with sendmail are visible to simple MUA testing.
In particular, do ALL of your sendmail configuration through the M4
macro files, rather than attempting to read and edit the .cf files.
Since your M4 files will quickly become site-specific, we recommend
copying the the full M4 setup to a local directory, and managing the
configuration from there. This will prevent a sendmail upgrade from
overlaying your site's configuration, something that has historically
been a problem to Solaris users, where a sendmail upgrade is included
in a patch cluster.
Management of sendmail .cf files through the M4 files is discussed in "Sendmail" chapter 4.
Virtual Domain handling: This refers to the case where a server at mydomain.net handles mail for otherdomain.com. The authoritative DNS for otherdomain.com is set with A and/or MX records pointing to the same IP as that for mydomain.net.
Handling this in sendmail is straightforward. Masquerading is covered in detail in "Sendmail" section 4.4, pp160ff. However, the discussion does not give a complete main.mc file masquerading configuration, which we include here for convenience:
MASQUERADE_AS(mydomain.net')dnl FEATURE(masquerade_entire_domain')dnl
FEATURE(limited_masquerade')dnl LOCAL_DOMAIN(mydomain.net otherdomain.com')dnl
MASQUERADE_DOMAIN(`mydomain.net')dnl
In short, you include all of the domain names you are handling, but only specify masquerading for domains where you need a nodename removed from the canonical name.
You also need to add the additional domain(s) to /etc/mail/local-host-names; each domain name on a separate line.
Note that "local-host-names" is actually optional feature for adding
names to the class $=w in the .cf file convention. It is typically
defined (by default) in cfhead.m4 (on Solaris 9,
/usr/lib/mail/m4/cfhead.m4)
define(confCW_FILE', MAIL_SETTINGS_DIR`'local-host-names')
For test, a simple local MUA should be able to send and receive mail from any of the domain names at your host. Make sure that the "host name this list prefers for email" on the main options page is correct for the masquerading you have set up.
Note that the list outgoing mail envelope is added by sendmail, and is not a Mailman function.
Relaying: Once upon a time, sendmail allowed significant relaying by default. Recent and current versions default to "no relaying at all." "Sendmail," section 4.5, pp164ff, discuss sendmail relaying in detail.
Solaris users should be aware that the Sun Solaris sendmail distributions have relaying enabled by default. For almost all installations, this should be corrected by changing the main.mc DOMAIN statement to: DOMAIN(`solaris-antispam')dnl
On non-Solaris systems, the usual DOMAIN statement is: DOMAIN(`generic')dnl