With b1gMail you can offer e-mail adresses to your users (user@your-domain.com or user@your.subdomain.com). All you need is a catchall function (*@domain.com -> pop3 account) and only one pop3 account. It uses PHP and stores the mails and other data in a MySQL Database.
Price: Free (GPL) - Added: 2002-10-25 - Hits: 369