Listar is a open-source (GNU Licence) software package that adminsters 
mailing lists (similar to Majordomo and Listserv).  Some of Listar's
features include:

       - A modular design structure, so that you can compile what you
         need (and don't)
       - The ability to strip down MIME messages and remove their
         attachments.
       - Ability to be run in a multi-Virtual Host configuration.

Take a look at Listar's website to get a full feature list:
 
WWW: http://www.listar.org/