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.

SOGo is a highly interoperable solution due to its adoption and promotion of open standards. Among those, SOGo particularly focuses on:


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.

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.

SOGo Connector

This extension transforms Thunderbird into a full DAV client for groupware servers such as SOGo.

  • Event organizers
  • CardDAV implementation for the address book
  • Support for WebDAV ACL

SOGo Integrator

This extension transforms Thunderbird in a pure “heavy” client for SOGo. Whereas the SOGo Connector is meant for portability (horizontal integration), the SOGo Integrator makes use of the features and layout of SOGo only (vertical integration).

  • Remote administration of folder subscriptions
  • Automatic replication of your local and subscribed folders
  • Automatic propagation of updates to chosen extensions from a local update server
  • Automatic propagation of default settings

SOGo Integrator is the perfect tool for managers of large-scale infrastructures who wish to easily deploy a native client on all of their users computers. With this extension, the amount of settings that the users have to configure is reduced to a minimum.

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.