User can’t access mailbox after migration to Exchange Online
After migrating a user mailbox to Exchange Online (from Exchange 2016) the user could no longer access their mailbox in Outlook, it gave no error just behaved as if it was offline. I tried removing the profile and creating it again but Outlook just reported that “Something has gone wrong”. Not very helpful at all!
After a lot of investigation the solution was simple: the RemoteRoutingAddress attribute for the user was wrong. I was able to check this using the Get-RemoteMailbox PowerShell cmdlet:
Get-RemoteMailbox -identity firstname.lastname@example.org | select *remote*
For some reason, the RemoteRoutingAddress attribute was set to email@example.com rather than firstname.lastname@example.org. I was able to correct this using the Set-RemoteMailbox cmdlet:
Set-RemoteMailbox -identity email@example.com -RemoteRoutingAddress firstname.lastname@example.org