I did a search here for a few of these keywords and got a lot of responses, but none (that I read) dealt with my specific issue.
We had a certain user leave our company a couple weeks ago. We disabled his exchange account, but did not delete it. Another user who is taking his place needs access to the ex-employees old emails. We figured it would be as simple as re-enabling the other users mailbox and assigning the new guy rights to it and then opening it the new guys Outlook.
Once we re-enabled the account, we cannot connect to his mailbox no matter what we do. We tried it on several PC's thinking maybe it was a software issue, but it didnt work on the three we tried it on, including the PC that this former employee used.
We have the error message (Event ID 9548) in the event log that mentions not having a "Master Account SID". Not sure if that would cause us to not be able to access this mailbox or not. I have also tried doing this same task with another user who recently left the company. Her account was still disabled and not yet deleted. Once I re-enable it, I can't access it either. Once I choose the profile to use upon starting Outlook, it gives me a login prompt where I have tried every combination of username and domain (including FQDN) possible.
I am sure there is probably some detail or setting we are overlooking, but cannot figure this one out.
Is there some other way to open an old users mailbox store in a current employees inbox?