Minimalist is a mailing list manager. It is small, fast, and easy to setup and maintain. It supports per-user settings, a write-only subscription option, multiple languages, a workaround for MIME-encoded messages, several levels of security, archiving, blacklisting, and more. It can be configured on a per-list basis as well as globally.
GPG-Ezmlm is an encrypted mailing list. PGP or GPG encrypted mails sent to the list are re-encrypted with subscriber keys, allowing for encrypted mail communications without requiring that all users know all other users' keys. Key exchange during list subscription is supported. It requires an existing Ezmlm installation to function.
Mailer is a program for managing email aliases in Unix. It allows users and administrators to easily create and manage email aliases. Mailer relieves administrators of the task from having to manually create aliases, and provides users with a powerful mechanism for setting up simple email lists and for redirecting their email without the use of .forward files.