@morrow without logs this will be hard to track down. can you ask your administrator to open up a support case for this?
Since the 26th of Februari the Zarafa Collaboration Platform is available in both the Fedora 11, 12, 13 and EPEL repositories. For more information, see https://fedoraproject.org/wiki/Zarafa. Many thanks to Robert Scheck and Jeroen van Meeuwen for the packaging, reviewing and all feedback.