Rspamd is an advanced spam filtering system featuring support for various internal and external filters such as regular expressions, suffix tries, RBLs, URL black lists, IP lists, SPF, DKIM, character maps, advanced statistics module (based on OSB-Bayes algorithm) and fuzzy hashes database that is generated based on honeypots traffic. Rspamd is designed to process hundreds of messages per second simultaneously without significant CPU load.
SOGo is a fully supported and trusted groupware server with a focus on scalability and open standards. SOGo is released under the GNU GPL/LGPL v2 and above. SOGo provides a rich AJAX-based Web interface and supports multiple native clients through the use of standard protocols such as CalDAV, CardDAV and GroupDAV, as well as Microsoft ActiveSync. SOGo is the missing component of your infrastructure; it sits in the middle of your servers to offer your users a uniform and complete interface to a
Jaro Mail is an integrated suite of interoperable tools for GNU/Linux and Apple/OSX to manage e-mail communication in a private and efficient way, without relying too much on on-line services, in fact encouraging users to store e-mail locally. Rather than reinventing the wheel, Jaro Mail reuses some existing free and open source tools working since more than 10 years, generating their configurations and setting up integrations automatically.