A previous admin installed a trail edition of Exchange 2013 in our 2007 environment for testing. When he tried to uninstall it there was an issue and it left some Exchange AD debris in the Active Directory structure.
Surprise, but now he is nowhere to be found.........
Now the company is going to upgrade and we cannot install Exchange 2013 because of these mailbox errors. The old server and database has been cleared out of ADSI and the one user that was in the old 2013 database has had all the Exchange attributes cleared from their AD profile.
We are still getting the "Database is mandatory on UserMailbox" error when I try to install Exch2013 on the new server. I tend to think there is some other mail-enabled object in AD that is causing the conflict, but I cannot find it.\
Obviously I cannot nuke the entire ADSI Exchange folder, because I still need 2007 to work. :-)
Any help would be appreciated......