Postlister is yet another PHP/SQL mailing list program. It features an unlimited number of lists, subscription confirmation, no browser time-out, different signature for each list, language files, and a password-protected browser-based administration area that allows you to create/delete/edit lists, find/add/delete subscribers, and preview/send mail to the list(s).
ezmlm-idx is an addition and patch to ezmlm, adding multi-message threaded archive retrieval, digests, remote administration, message and subscription moderation, subscriber-only restrictions, message trailer, subject prefix, subscriber name storage, customizable setup, multi-language and MIME support, and more. In addition, it has improved bounce handling, case-insensitive subscriber address storage, and support for distributed lists (main and sublist are transparent to the subscriber). It can be compiled with MySQL or PostgreSQL support.
Gutuma is a feature rich PHP newsletter/mailing list management tool that is designed to be easy to install and use. It doesn't require a database, yet offers multiple lists, import and export from CSV, file attachments, drafts, AJAX subscribe gadgets, administrator email notifications, MD5 protected logins, and batched deliveries that can be driven by a cron job.
Majordomo is a program which automates the management of Internet mailing lists. Commands are sent to Majordomo via electronic mail to handle all aspects of list maintainance. Once a list is set up virtually all operations can be performed remotely, requiring no intervention by the postmaster of the list site.
The QmailToaster is an RPM-based Qmail distribution for CentOS, Fedora, SuSE, and Mandriva. This system is designed for ease of deployment and includes strong anti-spam systems. This includes support for SRS, SPF, DomainKeys, and virtual hosting on the SMTP side. On the user side, this has a Web-based administration interface and supports POP3, POP3 over SSL, IMAP, and IMAP over SSL.
MailWatch is a program for analyzing mail traffic. As each message is received, Mailwatch records summary information about it. Later, it can generate a textual report, showing the number of posts during a time period, who the most prolific posters were, and what the most popular topics were. It is targeted at the end user who wishes to generate statistics for personal email or mailing lists.