Zimbra Support
Zimbra is an alternative to Microsoft Exchange Server. Zimbra is a complete email, address book, calendar and tasks solution that can be accessed from the Zimbra Web Client, Zimbra Desktop offline client, Outlook and a variety of other standards-based email clients and mobile devices.
Zimbra is an open source software. It can be deployed as a traditional binary install on Linux, or as a software virtual appliance, commonly referred to as Zimbra appliance.