Mailman
GNU Mailman is software to help manage email discussion lists, much like Majordomo and Smartmail. Unlike most similar products, GNU Mailman gives each mailing list a web page, and allows users to subscribe, unsubscribe, etc. over the web. Even the list manager can administer his or her list entirely from the web. For full information on this product, please see
http://www.list.org/ or
click here for complete documentation.