Ichabod is being rewritten at the moment, and is not in a stable state. Please check back in a few weeks, or contact us, and volunteer to help.
If you need an open source mail server at the moment, we'd suggest
Ichabod is a mail server written entirely in Java. It supports SMTP and POP3. It is administered via the web, or via email.
Ichabod is extensible. You can add your own email processing functionality by subclassing. Existing subclasses include Mailing Lists, Forwarders, Email Administration, Heartbeat Notifications, etc.
See the FAQs available for Ichabod for more info.
Ichabod has been around since 1997, slowly growing in functionality. It's running on a small number of sites around the net, such as The Software Development Forum. More users and developers are needed to keep it growing.
Visit the project page at http://sourceforge.net/projects/ichabod/