Kolab Clients

Any standard client can connect to the various services a Kolab Server provides, e.g. Email (SMTP, POP3, IMAP), Calendar services (CalDAV), Addressbook/Management (LDAP, CardDAV) or Freebusy lists (HTTP).

For an integrated groupware experience, more is needed. Clients must understand the Kolab3 storage format and have necessary features, like setting access controls, dealing with iCalendar emails and freebusy lists. Any non-web client must also offer offline support and should do electronic signatures.

We encourage anyone to implement Kolab features in their email, addressbook or organizer applications. There's a library available that reads and writes the kolab format. An entry in the following list of potential Kolab clients subsequently does not necessarily mean endorsement.

If you are looking for instructions for how to set up these clients, please see the list at MyKolab.com.

Professionally Supported Clients

The following clients are stable and therefore recommended. They are professionally supported by Kolab Systems, Bynari, KONSEC or other companies.

Kontact - The Kolab Desktop Client


  • License: Free Software - GNU GPL
  • Status: stable
  • Download: Debian, Windows and MacOS
  • Compatibility: Kolab Storage Format v1, v2 and v3 since Kontact v4.9

The Kolab Desktop application is based upon KDE Kontact. You may either choose one of the regular versions that come with your software distribution or the versions packaged by the Kolab Community.

The KDE Kolab Client is based on other KDE software like KMail, KOrganizer and KAddressbook. All development of the Kolab community is done within the KDE software repository and contributed directly to KDE. It runs whereever KDE runs. KDE 3.5 is suited for POSIX and GNU like systems, e.g. GNU/Linux. KDE 4 will also run in Mac OS X and Windows.

In addition there are special branches of KDEPIM that cater specifically to enterprise users. The Kolab Community helps to maintain theses branches.

  • Kontact enterprise 35 (e35)

    For use in production grade systems, we recommend the "enterprise35" branch of KDEPIM, which can be build on to of KDE 3.5.
  • Kontact enterprise 5 (e5)

    Enterprise5 is the current desktop version of Kontact for GNU/Linux, Windows and Mac OS X, based on KDE4.
  • Kontact Touch

    Kontact Touch is a port to touch screen devices (like mobile handsets or tablets). Currently, it works on Maemo, MeeGo and Windows Mobile 6.5. Read the KDE Kontact Touch page for more details and screenshots.

Roundcube (Webmail)

Roundcube - open source webmail software

Roundcube provides a desktop-like user interface which is easy to install/configure and that runs on a standard LAMPP server. The skins use the latest web standards such as XHTML and CSS 2. It is multilingual and supports find-as-you-type address book, Richtext/HTML message composing, searching for messages and contacts, threaded message listing, shared folders and ACLs, a full featured address book as well as an extensible using the Plug-in API.

The Kolab Community works closely with Roundcube to bring full Groupware functionality to this excellent webmailer. Several plugins have been developed that enable this functionality in Roundcube.

Professionally Supported Mobile Client Services

Kolab ActiveSync Server

The Kolab ActiveSync Server allows users of ActiveSync-capable clients to access their server mailboxes and have Kolab-provided PIM-functions available. It uses Syncroton, a PHP library for the ActiveSync protocol which is used by Tine 2.0 and Kolab to provide synchronization of contacts, events, tasks and emails to their users. If you would like to contribute join its developers mailing list. All contributions are welcome.

Z-Push (ActiveSync Interface, deprecated)


Z-Push is an implementation of the ActiveSync protocol which is used 'over-the-air' for multi platform ActiveSync devices, including Windows Mobile, iPhone, Android, Sony Ericsson and Nokia mobile devices. With Z-Push a Kolab Server is connected and synced with these devices.

Proprietary Connectors for Microsoft Outlook

Bynari Connector for Microsoft Outlook


The Bynari Outlook Connector is a complete Outlook MAPI Message Store Provider. It keeps Outlook synchronized to the IMAP server, providing an Exchange-like experience for the end-user. The Connector gives users a complete Kolab Groupware/Collaboration experience with full support for calendaring, contacts, tasks and notes.

The Bynari Connector 4.0 for Microsoft Outlook supports the Kolab 2 XML Storage format and the Kolab 2 server. It features several performance enhancements, sieve rules/vacation notification, mobility support for cradle sync, enhanced offline support and more.

The Bynari Connector supports Outlook 2010 (32 bit & 64 bit) as of January 2011. Messages are instantly accessible. Kolab Systems certified the Bynari Insight Connector in 2010 (official test report) to work properly with Kolab v2.2.4 on various Windows environments.

KONSEC Konnektor for Microsoft Outlook


The KONSEC Konnektor is a Microsoft MAPI Storage Provider supporting the Kolab 2 XML Storage format and the Kolab 2 server. It was designed to be interoperable with all Kolab 2 clients and special attention was given to support Microsoft ActiveSync (Pocket PC PDAs) and Palm Pilots. The KONSEC Konnektor fully supports Kolab 2 shared public folders including folders containing calendars, tasks and contacts. In case features are required which cannot be properly expressed using the current Kolab XML format a fallback to TNEF is configurable.

Toltec Connector for Microsoft Outlook


The Toltec Connector synchronizes the calendars, contacts, tasks, mails and other folders in Microsoft Outlook to an IMAP4 server. This enables you to share the information on the server with other Toltec enabled Outlook mail clients. Using the Toltec Connector with the Kolab-XML format you can share the information with other Kolab-XML clients like Kontact and Horde aswell. Using the Toltec Connector you can share folders between different Outlook users and between Outlook and Kontact and/or Horde. The Outlook data on the server provides a backup for PST corruption or hardware failure on the client side.

Other Clients

Not all clients are developed for professional service and support. Some are developed by volunteers or professionals out of interest for the technology, to solve an individual problem, or for single customers with particular needs. There are no warranties, liabilities or guarantees of support options for these clients. They are nonetheless useful for many users. Many of these clients are also developed by groups of developers which welcome participation and contribution. Please feel encouraged to help improve the clients you find useful.

SyncKolab (Thunderbird plugin)


SyncKolab was written to add Kolab functionality to Thunderbird, Icedove and Seamonkey. SyncKolab utilizes selected IMAP folders to synchronize them with the local address book, calendar and tasks. It has been successfully tested under Thunderbird for Windows, Linux and MacOSX.

For calendaring and tasks, a suitable release of Lightning for the installed Thunderbird-, Iceweasel- or Seamonkey-version must be used.

We provide a HowTo for using Thunderbird/Lightning with Kolab

Horde (Webmail)


Horde allows users to access their server mailboxes and have full groupware functionality available. The Kolab Server v2 comes with version 3 of the framework. A Kolab backend for Horde 4 is currently under development.

Old versions of Kolab offer a SyncML interface through the Horde Webclient. It allows users SyncML-capable mobile phones to access the Kolab-provided PIM-functions. In this scenario email will be handled by an IMAP client on the mobile device.

Evolution extension: evolution-kolab


evolution-kolab extends GNOME's Evolution and Evolution-Data-Server (EDS) to become a full-featured Kolab-client. Besides an Evolution-"EPlugin", evolution-kolab provides the following extensions to EDS: A "CamelProvider" named "kolab2", an "ECal"- and "EBook"-backend for Kolab, along the Camel-/EDS-libraries "libekolab", "libekolabutil" and the conversion-library "libekolabconv", which transforms iCal from and into Kolab-XML.

Building and installing binaries for Debian 6.0 "Squeeze" works, Any packaging effort for GNU/Linux distributions is very welcome.

Kolab Sync for Android: kolab-android

The kolab-android connector synchronises Android's addressbook and calendar to an IMAP-folder in the Kolab2 format. More information can be obtained through kolab-android's wiki, and the mailing-list.

Kolab Sync for Outlook: kolab-outlook

The kolab-outlook connector synchronises Outlook's contacts and calendar to an IMAP-folder in the Kolab2 format. More information can be obtained through kolab-outlook's wiki, and the mailing-list.

Syncphony: A Funambol connector

Syncphony (initially "kolab-sync") is a Funambol connector, connecting Kolab-WS with a Funambol sync-server, thus enabling all devices supported by Funambol (e.g. "feature phones" and "smart phones") to synchronise their PIM-Data with a Kolab Server. Further details are provided in Syncphony's wiki.

Kolab-WS: Kolab functionality as web-service

Kolab-WS extends Kolab to provide Kolab functionality as a web-service. Kolab-WS was originally part of Syncphony, which utilises Kolab-WS since their split. Further details are provided in Kolab-WS's wiki.