SOGo is a reliable and supported groupware server that prioritizes scalability and open standards. It is released under the GNU GPL/LGPL v2 and above. What sets SOGo apart is its robust AJAX-based Web interface and compatibility with various clients through protocols like CalDAV, CardDAV, GroupDAV, and Microsoft ActiveSync. Acting as a crucial link in your server infrastructure, SOGo provides users with a unified and comprehensive interface to access their information. It has been successfully used in large-scale production environments with thousands of users. Explore more about SOGo to leverage its unique functionalities.
https://www.sogo.nu/