Sympa is scalable and highly customizable mailing list manager. It can cope with big lists and comes with a complete Web interface. It is internationalized, and supports the us, fr, de, es, it, fi, and chinese locales. A scripting language allows you to extend the behavior of commands. Sympa can be linked to an LDAP directory or an RDBMS to create dynamic mailing lists. Sympa provides S/MIME-based authentication and encryption.