I'm currently working on migrating our exchange 2007 mailboxes to office 365. I've created some migration endpoints to move a select few mailboxes to the cloud according to the following guide from Microsoft:
Everything has worked great. I create the endpoint, start the batch and a mailbox is successfully synced to O365 and has a status of synced.
However when I change the on premise mailbox to a Mail enabled user using the provided power shell scripts, the status of the batch migration shortly switches to failed. Presumably because the mailbox is disconnected from the on premise exchange when its converted to a mail enabled user. The error I receive is MapiExceptionUnknownUser
The mailbox on office 365 works and all mail flow works on...