@morrow without logs this will be hard to track down. can you ask your administrator to open up a support case for this?
Nowadays, email is one of any company’s mission-critical applications. Zarafa’s open source groupware combines the usability of Outlook with the stability and flexibility of a Linux server. Not only is Outlook supported natively, but users can also use WebAccess, which has the same look and feel as Web 2.0 Outlook, all ActiveSync-compatible mobile devices and BlackBerry handhelds via the BlackBerry Enterprise Server.
Not only can you access your private email, but Zarafa also allows you to share your mailbox with colleagues via an advanced permissions system.
Group mailboxes and public folders can be used for all incoming information, support or sales emails and with the server-side rules wizard you can organize your email automatically.
Share calendars, plan meetings with your colleagues with free/busy information, send meeting requests or book resources. You can use any of these features via the Outlook client or Zarafa WebAccess.
The CalDAV gateway even synchronizes your calendar with other clients.