I believe the "MAPILogonEx Failed: 80004005" error is caused by attempting to run Outlook/Exchange Migration Wizard on the actual Exchange server.
See this thread...
[SOLVED] Exchange Migration Wizard not copying mails
And these results turfed up from a google search...
Exchange and Outlook On The Same Machine - SGriffin's MAPI Internals - Site Home - MSDN Blogs Microsoft does not support installing Exchange Server components and Outlook on the same computer
The error you are seeing is nothing to do with Zimbra. Microsoft highly discourages using Outlook on the actual Exchange server. I believe Exchange Server doesn't have the necessary binaries/API to actually run Outlook.
All this was certainly the case with previous versions of Exchange/Outlook, not sure about 2010. There are probably ways round it but I didn't want to bork up our Exchange server. I found this out when looking to migrate from SBS 2003 a year or so from a remote location.
Try installing Outlook and setup a profile on a different machine to the Exchange Server then run the Migration Wizard from there.