Mailman, the "GNU Mailing List Manager," "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."
GNU Mailman is commonly used for e-mail lists. It has not been localised yet in any African languages (as of 2007).