By design, the mailbox remains online when it is moved to Exchange Online or when it is moved between Exchange servers. This lets you access the mailbox during the move. After the move is complete, you are prompted to restart Outlook or to log off from or on to Outlook Web App if the server is in a new Exchange site or forest. This behavior makes sure that the client starts to use the correct Exchange endpoint for all connections.
If changes are made to the Exchange server endpoint, or if public folder databases that are referenced by the current Exchange database are changed, you should also be prompted to restart Outlook.
If you continue to be prompted to restart the Outlook client, follow these steps:
- Make sure that you restart Lync or Skype for Business if your mailbox was recently moved or if a change was made to the Exchange endpoint.
- Confirm that you have the most recent update for Outlook installed. Updated information and links to the most recent updates for Office 365 are available at Outlook Updates.
- If steps 1 and 2 don't resolve the issue, enable Outlook logging. Instructions are available at What is the Enable logging (troubleshooting) option?
- After you've captured the issue by enabling logging, submit an escalation to Microsoft Online Services Support for investigation. Include the following details:
- Outlook logs
- Approximate number of times that you've been prompted to restart
- Time and date of the most recent occurrence
- Action that was taken just before you were prompted. For example:
- At the first start of Outlook
- After you sent email
- While you checked an address book entry
