I’ll make this post short and sweet.
Two days ago, I attempted to back up several user mailboxes for a client by using Exmerge. I attempted to run Exmerge using the Administrator account which, by design, did not work. The process would start, then fail with an error saying that the necessary rights weren’t in place, etc., etc.
So I followed the steps in an MS knowledgebase article to create a separate account, in a newly-created separate group, and granted said group the necessary permissions to run Exmerge. It didn’t work, and failed with a different error than when I ran Exmerge as Administrator. So I read up on that error, and followed more steps to resolve it. They too, did not work. So I fiddled with permissions a bit myself, all the while trying to avoid just granting EVERYTHING to the group ALL OVER the server (and I even did try that – still didn’t work).
Finally, I settled on a Technet article which walked through the errors I got, and indicated that the mailbox store was not mounted. Just to appeal to my own sanity, I verified that it was indeed mounted, because I could run Exmerge as Administrator and see mailboxes. While I was looking at Exmerge, again, as Administrator, I accidentally clicked the “next” button instead of cancel and, to my surprise, it worked.
And it’s not supposed to.