I am in the process of transitioning Exchange 2010 to Exchange 2016. Have moved several mailboxes to Exchange 2016 that are being successfully accessed with Outlook and OWA. However, there is one mailbox (we'll call the user John Doe) that was successfully moved and the mailbox is accessible via OWA but not accessible with Outlook. Attempted to connect from several other workstations and Outlook clients but same result. We move the mailbox back to Exchange 2010 and everything works without issue.
Then we exported the John Doe mailbox to PST, deleted it from Exchange 2010, created a new mailbox for John Doe in Exchange 2016, and imported PST. Outlook is unable to connect to the mailbox on 2016. If we move the mailbox back to Exchange 2010, Outlook is able to access the mailbox without issue.
It appears the auto-configutation is working properly as the user's mailbox info populates Outlook when the profile is being created. We've even deleted the Windows profile from on of the workstations but made no difference.
Any thoughts that could guide me?
Thank you in advance.