MailMan - Maling List Manager

http://www.list.org/features.html

Mailman, the GNU Mailing List Manager
Mailman is free software for managing electronic mail discussion and e-newsletter lists. Mailman is integrated with the web, making it easy for users to manage their accounts and for list owners to administer their lists. Mailman supports built-in archiving, automatic bounce processing, content filtering, digest delivery, spam filters, and more. See the features page for details.