I recently paved a new machine and had to put GroupWise on it.  To make a long story short, the machine got into a state where I would receive a message like "The MAPI Session Handle of the Novell GroupWise ‘Object Request broker’ could not be accessed. The address book cannot run" every time I tried to compose an email.

A lot of searching turned up very little help.  Novel had a craptastic answer regarding this, suggesting that you uninstall everything including Outlook and then reinstall.  But this issue is related to the MAPI client not being installed properly.  You don’t have to reinstall GroupWise like other sites suggest, rather just install the MAPI client from Microsoft.  After I installed the MAPI client, Groupwise works as it should…