4.2. Which MTA should I use with Mailman?
Many MTAs can be used with Mailman, and all the most common MTAs on the Internet:
Mailman is MTA agnostic and will generally support anything that understands standard SMTP and can deliver a message to a local program.
As for which MTA to use? That is a local site decision and should be governed by local expertise, and requirements such as performance, security and compatibility. There is a summary of the four most popular MTAs at http://shearer.org/MTA_Comparison .
Some additional commentary may help:
Courier: courier is a new player when compared to other MTA's. Courier is an MTA that contains the standard SMTP server, as well as IMAP, POP3, webmail, and other features. This turns out to be quite an advantage as far as integrating these services is concerned. All of the tools use the same databases for authentication, read and write the same mailboxes, etc. The documentation is relatively good, and configuration can be done with little difficulty. If you don't want to edit configuration files, Courier also comes with a tool called webadmin to help with this. The performance and security of Courier is not as well tested as with other MTA's because of its young age. Also, if you are using mailboxes in the standard mbox format rather than maildirs, it is not recommended that you use Courier because some of its features don't operate properly with mbox. If you only want an MTA, it doesn't come separately from the other functionality.
Exim: Of all the commonly used MTAs Exim is probably the easiest for non-experts to setup and configure. The configuration file is easily read and understood by non-experts, the documentation is unusually clearly written and thorough, and the author and user community actively support and help users. Exim is also among the most configurable and easily extended of all MTAs. Exim makes it easy to do very clever and strange things with mail systems. Nigel Metheringham has written a particularly good HOWTO (http://www.exim.org/howto/mailman.html) on configuring Exim for Mailman. Exim is highly recommended for smaller sites, people new to mail systems, and sites that need strange/unusual mail configurations. Since 2000 or so Exim has had an excellent security history. Note: Exim is the default MTA for Debian/Linux.
Postfix: Postfix aims to be an extremely secure and fast MTA. It is built on the principle of many small, simple, easily reviewed (for security concerns) programs that don't trust each other but operate together to process mail. Postfix is a fast MTA, has an excellent security history, a single active and helpful developer. Postfix comes with a very highly commented default configuration file and lots of reasonable built-in defaults, and is one of the easiest MTAs to setup and configure (experts are split on whether exim or postfix is easier in this regard). Postfix is highly recommended for sites that have security concerns, or high performance requirements (though Exim's performance curves are quite similar). Like qmail and Exim, Postfix tries to be a drop-in replacement for sendmail, working with the same command names and command-line options, etc... Postfix goes one further and supports Sendmail milters! If you have been using sendmail and are looking for a replacement, postfix is likely to be the easiest and least painful way to make that change. Postfix also has many default features that make it well-suited to handling mailing lists with out-of-the-box configurations, such as hashed mail queue directory structures, parallel delivery, bounded exponential backoff on errors (so that you don't get a "thundering herd" of servers that all try to bury a particular remote site right after it comes back up). Glenn Graham has an excellent article on postfix entitled "Postfix: A Secure and Easy-to-Use MTA" (http://www.onlamp.com/lpt/a/4099/). Note: Postfix is the default MTA for Mandrake/Linux.
Qmail: Qmail is the dark horse. Fast, stable (code untouched since 1997), good security history (only one published root exploit), similar architecture to Postfix (in some ways Postfix was inspired by Qmail), funky licensing (it is NOT Open Source), highly abrasive author, very odd/non-standard configuration. Qmail can also be difficult to integrate with external mail systems such as Mailman). It does not follow commonly used Unix standards and patterns. See http://shearer.org/MTA_Comparison for a more thorough comparison. Basically, if you aren't a qmail user already, there should be no need to become one unless you have very special circumstances or just like the approach.
Sendmail: The old man on the block and the default MTA for most commercial Unixes, expected to be replaced around 2008 by Sendmail X. Probably the closest thing you'll ever see to a totally unreadable gibberish config file and the documentation is not a whole lot better. Historically, Sendmail has had a poor security history and quite horrible performance. Recent versions of Sendmail have significantly improved both problems, bringing Sendmail moderately close (if not quite matching) to other more modern MTAs like Exim and Postfix. Due to its unreadable configuration file, faulty performance and security history Sendmail is not generally recommended unless you happen to already have a local Sendmail expert.
However, sendmail is the default in many non-Linux flavors and distributions of Unix-like operating systems, and for these OSs may be the easiest to implement simply because it's already there. Configuration has been made quite easy when done properly through m4 instead of sendmail.cf, and many graphical tools are available for more intuitive configuration.
With appropriate work, sendmail can be configured to be a fast and high-volume general-purpose MTA. This takes knowing what you're doing, making suitable configuration changes, and daily care-and-feeding.
Last changed on Fri Jan 25 00:10:43 2008 by jidanni
Converted from the Mailman FAQ Wizard
This is one of many Frequently Asked Questions.