Postlister is a PHP/SQL-based mailing list program. Main features include: Unlimited number of lists, browser-based administration, different signature for each list, language files, subscribe/unsubscribe confirmation (an email is sent to the person who wants to subscribe/unsubscribe, asking him/her to go to a certain URL to confirm the request), no browser time-out (allows for large lists), automatic line wrapping, and much more.