OpenWebMail is a full-featured Webmail, address book, calendar, and Webdisk system that is designed to manage very large mail folder files in a quick and memory efficient way.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.
Support for virus scanning using clamav, spam
checking with SpamAssassin, spamlearn support,
background mail filtering, MS-TNEF support, lightbar
quick selection, multiple message forwarding,
auto-login, speed improvement for large folders, and
two security fixes. There were also many other minor
improvements and bugfixes.