Share your calendars, tasks, address books, and web access your email with a free and open source solution.

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 access their information. It has been deployed in production environments where thousands of users are involved.


SOGo offers multiple ways to access calendaring and messaging data. Your users can either use a web browser, Microsoft Outlook, Mozilla Thunderbird, Apple iCal, or a mobile device to access the same information.

CalDAV: The Calendaring Extensions to WebDAV protocol is vastly popular among clients (Apple iCal, Mozilla Ligthning / Sunbird, etc.) and allows them to exchange calendar components with servers that support it.
CardDAV: In its fourth revision, vCard Extensions to WebDAV is to address books / contacts what CalDAV is to calendaring. Less popular than CalDAV, it’s nevertheless quickly gaining momentum and is used by the SOGo Connector extension.
Mail protocols: For messaging, SOGo fully makes use of standard protocols such as IMAP and SMTP, with Dovecot Sieve integration to filter incoming email.
Microsoft Exchange ActiveSync: The de facto standard for synchronization of email, contacts, events, and tasks with mobile devices that use Apple iOS, Android, Windows Phone or BlackBerry 10.

Supporting open standards provides SOGo with extensive interoperability, scripting capabilities and more.


Mozilla Thunderbird

Inverse has worked to make Mozilla Thunderbird the best Open Source, multi-platform, native client to SOGo. In order to reach this high level of interoperability, two extensions were developed for Thunderbird and its official calendaring complement, Lightning. Nonetheless, SOGo also supports other native clients such as Apple Calendar, Apple Contacts, Microsoft Outlook and any CalDAV and CardDAV client.

Microsoft Outlook

CalDavSynchronizer is a free Outlook Plugin which synchronizes events, tasks and contacts between Outlook and Google, SOGo, Nextcloud, Horde or any other CalDAV or CardDAV server. Supported Outlook versions are 2019, 2016, 2013, 2010 and 2007.