hMailServer was a free email server for Windows created by Martin Knafve. It ran as a Windows service and includes administration tools for management and backup. It had support for IMAP, POP3, and SMTP email protocols. It could 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 were stored on disk in a raw MIME format. As of January 15th, 2022, active support and development were officially halted,[2] although version 5.6 will continue to receive updates for critical bugs.
Common features such as multiple-domain support, aliases, catch-all and basic mailing lists were present. Users could be authenticated both against the local hMailServer user system and against an external Active Directory.
AntiSpam
hMailServer offered a number of different AntiSpam mechanisms:
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.[3][4] Since version 5.4, hMailServer is licensed under the GNU AGPL 3.[5][6]
The latest version of hMailServer appears to be open source again.[7] This is also noted on the hMailServer home page.[8]
^"Functionality". hMailServer. Retrieved March 5, 2012. hMailServer 4 and earlier versions are licensed as open source under the GPL license. Later versions of hMailServer (version 5 and later) are still free of charge but closed source.
