- In Outlook Web App: You weren't able to sign in because the mailbox is being moved. You won't be able to access it until the move is complete. Please wait and try again later.
- In Outlook: Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintenance.
- The mailbox database was moved within the same environment.
- There was an internal migration from one environment to another (for example, from Exchange Server 2010 to Exchange Server 2013).
The last stage of a mailbox move consists of the final delta sync to make sure that all data in the original mailbox is migrated. In this situation, users may not have access to their mailboxes for 2–5 minutes, but it may be longer for larger mailboxes. If a user reports a problem accessing their mailbox for longer than 15 minutes, escalate the incident to Microsoft for investigation.
Article ID: 3136658 - Last Review: Jan 20, 2016 - Revision: 1