I've been working with Microsoft for nearly a month on this issue and we just aren't making progress.
I have an RBAC role group that contains the Mailbox Import Export role. The user is assigned. The user is also a member of Domain Users -- and no other groups.
All we know, at this moment, is if we add the user to the Exchange Admins group, the New-MailboxExportRequest works. Without that group, he gets that error that the SystemMailbox could not be found.
It seems like an AD issue --- some rights are not being granted correctly? Or something is being denied?
The SystemMailbox that cannot be found is the one for the Database of the target mailbox we are trying to export. Somehow, the user who is trying to export doesn't seem to have access to the SystemMailbox on the other database.
Bearing in mind that this functions correctly if the user is in the Exchange Admins group, it would appear that on the Exchange side, all the parts are at least working correctly. The problem must be specific to some kind of AD rights for the user.
My question, more than anything, that Microsoft cannot answer is this:
What rights --- exactly --- are required to do a New-MailboxExportRequest?
Assume that we have disabled / denied ALL rights across the board. Which would have to be set to Allow for this cmdlet to function? For the user & Exchange Trusted Subsystem (and whatever other account requires rights for this)?
Thanks!