Sympa is a scalable and highly customizable modern mailing list manager capable of handling big setups: 20.000 lists with 700,000 subscribers.

Here are some of its many features: - Advanced MIME support, including digests, anonymization and S/MIME encryption - Builtin password-based authentication, HTTPS X.509 certificates or use of LDAP database or Single Sign-On CAS or Shibboleth servers - Archive management with web access and RSS feeds - Moderation and administration via email, web and SOAP interface - Multi-lingual, translated to more than 30 languages - Virtual domains (virtual robots) - Local SQLite subscriber database or use of MySQL, PostgreSQL or LDAP - Integrated scripting language to extend and automate routines - Web interface called WWSympa providing homogenous access for both users and admins to list overviews, customization, administration, searchable archives and optional web-based email reply form. - Clean moderation and expiration processing - Customizable service messages (templates) for owner and listmaster - Semi-automatic bounces management

SYMPA is French for 'SYstème de Multi-Postage Automatique', which means 'Automatic Multi Mailing System'.