Zimbra

Zimbra (Zimbra Collaboration, known before 2019 as the Zimbra Collaboration Suite or ZCS) is a collaborative software suite combining an email server and a web client. It provides email, calendaring, contacts, tasks, file sharing and chat, accessible through web, mobile and desktop clients, and is offered in both open-source and commercially supported ("Network Edition") forms. The Network Edition adds closed-source components such as a proprietary MAPI connector to Outlook for calendar and contact synchronization, and connectors/ActiveSync support available only in the commercial version.

The server component exposes a SOAP API to its functionality and also acts as an IMAP and POP3 server, running on Linux distributions (and on other operating systems via virtual machines or containers). It supports CalDAV, CardDAV and SMTP for messaging, LDAP for directory services and Microsoft Active Directory, uses Postfix as its MTA, and incorporates ClamAV, SpamAssassin and DSPAM for anti-malware and spam filtering plus S/MIME for signing and encryption. Zimbra synchronizes mail, contacts and calendar with clients including Mozilla Thunderbird, Evolution, Microsoft Outlook and Apple Mail, and offers native two-way sync with mobile devices. The Zimbra Web Client provides document sharing, chat, videoconferencing, advanced search, online document authoring, "Zimlet" mashups and an administration UI, and is built with the Zimbra Ajax Toolkit. A separate desktop client, Zimbra Desktop, was discontinued under VMware in 2013, restarted in February 2014 and ended again by 2019.

Core functionality also covers shared calendars with real-time multi-user viewing and editing, resource booking for rooms and equipment, and iCalendar compatibility for interoperability. Under Synacor the product line has been developed into the Daffodil suite (version 10 as of 2025), with modern web applications, additional security features and integrations for hybrid work including video conferencing and document collaboration.

Founding story

Zimbra was founded in December 2003 by Satish Dharmaraj, Ross Dargahi and Roland Schemers as Liquid Systems, Inc. in San Mateo, California, with the founders drawing on prior experience in unified messaging to build a web-based collaboration platform based on open standards. The company worked in stealth mode before rebranding to Zimbra, Inc. in mid-2005. According to former Zimbra President and CTO Scott Dietzen, the name derives from the Talking Heads song "I Zimbra"; one source also notes a possible association with the Portuguese word for juniper.

Business model

Zimbra distributes a dual-edition product: a freely available open-source edition maintained as a community initiative, and commercial editions (Network Edition) sold with advanced features, proprietary connectors and support for large-scale deployments. Sources note that in later versions most components remain open-source but official binary builds are no longer free to download and use. Synacor has said it would continue the open-source version and provide technical support for the Open Source Edition through its VAR partners.