I had Blackberry Enterprise server installed on the Domain controller, but it has caused problems.
I have been able to successfully move BES back to its original server, but I also noticed that a full Exchange server information store was created on the DC.
When I try to uninstall Exchange I get the above mentioned error.
Following a similar experts-exchange listing, I was able to determine using ADSIEDIT that the original mailbox owner 'mail man' has been deleted.
How can I change the msExchAdminMailbox to an account that exists?
I never used any of the mailboxes on this server, because I never wanted the full installation of Exchange to occur on this machine.