SOGo

SOGo is an open-source groupware server that provides shared email, calendars, and address books through a single interface. It is designed to integrate with existing infrastructure such as Microsoft Active Directory, OpenLDAP, SQL databases, and IMAP servers, and can be deployed using ZEG for environments without existing services. The software is released under the GNU GPL/LGPL v2 and above.

SOGo offers an AJAX-based web interface with features including drag-and-drop, reminders, delegation, resource reservation, HTML mail composition, mail identities, return receipts, auto-reply and forwarding, S/MIME, single sign-on via CAS, WebAuth or Kerberos, sharing, recurring events, free/busy time, notifications, categories, multiple IMAP accounts, server-side mail filtering, export/import, two-factor authentication, and password policies. It supports CalDAV, CardDAV, GroupDAV, IMAP, SMTP, and Microsoft ActiveSync, enabling access through web browsers, Microsoft Outlook via the Outlook CalDav Synchronizer, Mozilla Thunderbird via the SOGo Connector and SOGo Integrator extensions, Apple Calendar and Contacts, and mobile devices.

SOGo is intended for organizations and communities that need shared groupware services at scale. It is available as a free and open-source solution, with packages for Debian, Ubuntu, Red Hat Enterprise Linux, and CentOS. An online demo with three accounts is available for evaluation.