Hi,
I've created a cut-over migration batch. The initial sync went fine. Now I'm at the stage to do the final transition. So I decided to do a last sync in order to have the latest e-mail synced to office 365. To do this I clicked on the 'play' button for the migration batch. Problem now is, that the sync fails for Exchange Online mailboxes that have connected once to Outlook 2013. The sync for this mailbox fails with the error 'Error:ProvisioningFailedException: The name "<user name>" is already being used. Please try another name.'
Thing is that for all other mailboxes the sync still works fine and latest mails from on-premise Exchange are being synced, but once I connect Outlook 2013 to the Office 365 mailboxes, these mailboxes also start to fail the sync. What's happening here? How can I do a final sync before I know for sure that all mail is being routed to exchange online instead of our local Exchange server?
I want to have the migration batch in place and syncing until I know for sure that all mail is being delivered to office 365 while the clients are already connected to Exchange Online.
Franc.