To resolve this issue, use one of the following methods, as appropriate for your situation.
Domain moves
If an account must be moved between domains, use a process that keeps the objectGUID of the account. To do this, use migration tools such as Active Directory Migration Tool (ADMT) in move mode instead of in clone mode. For more information about how to use ADMT to migrate and restructure AD DS domains, visit the following Microsoft website:
For MMSSPP 11.1 or a later version: Forest moves, accidental deletions, or employee status changes
Use the Automatic Service Reconnection (ASR) feature of MMSSPP 11.1 or a later version if an account must be moved between forests or if the account is accidentally deleted. This feature indicates the objectGUID of the original source AD DS account for the new account. The original mailbox can be connected to the new account without any manual intervention.
For more information about the ASR feature for MMSSPP 11.1 or a later version, see the following Microsoft article:
For MMSSPP 10.3 or an earlier version: Forest moves, accidental deletions, or employee status changes
Microsoft must manually restore the content of the old mailbox to a newly provisioned mailbox. Make sure that the original AD DS account is deprovisioned, and then escalate the case to Microsoft. To escalate the case, please use the
Exchange Online topic and the
PST capture, transfer sub-topic when you
submit a support incident online to Microsoft Online Services Support, or
contact Microsoft Online Services Support by telephone .
Note Do not escalate issues to Microsoft if there are two active accounts and mailboxes. By default, disconnected mailboxes are purged from mailbox databases within 30 days. To avoid content loss that occurs after a 30-day disconnection, contact Microsoft Online Services Support by
online submission or by
telephone immediately.