HMailServer


hMailServer is a free email server for Windows created by Martin Knafve. It runs as a Windows service and includes administration tools for management and backup. It has support for IMAP, POP3, and SMTP email protocols. It can use external database engines such as MySQL, MS SQL or PostgreSQL, or an internal MS SQL Compact Edition engine to store configuration and index data. The actual email messages are stored on disk in a raw MIME format. It has active support and development forums.
Common features such as multiple-domain support, aliases, catch-all and basic mailing lists are present. Users can be authenticated both against the local hMailServer user system and against an external Active Directory.

AntiSpam

hMailServer offers a number of different AntiSpam mechanisms:
hMailServer has built in support for ClamWin/ClamAV. It's possible to execute any command line virus scanner.

Other features

The hMailServer project was started in 2003. Up until 2008 and version 4, the project was licensed under the GPL. Versions 5.0 to 5.3 were proprietary. Since version 5.4, hMailServer is licensed under the GNU AGPL 3,.

The current version of hMailServer appears to be open source again This is also noted on the hMailServer home page.