@morrow without logs this will be hard to track down. can you ask your administrator to open up a support case for this?
ClearCenter (in collaboration with ClearFoundation, a non-profit organization) creates, distributes and maintains ClearOS - an open platform for Network, Gateway and Server. ClearOS is focused on providing choice to organizations around what, where and how their IT infrastructure is deployed.
Zarafa's Community, Small Business and Professional Editions are available from ClearCenter's Marketplace for ClearOS - a simply and intuitive framework for installing and configurating software to extend the core functionality of the ClearOS platform. Zarafa is the recommended solution for organizations and users looking to deploy email and collaboration services on-premise or in a private-cloud.
Zarafa Small Business and Professional Editions are available for ClearOS Professional Edition. ClearOS Professional is available here. Zarafa Community Edition is available for all ClearOS versions. ClearOS Community Edition can be downloaded via the ClearFoundation website here.