I currently have coexistence setup with Exchange 2010 and 2016. When I move a mailbox to 2016, existing profiles in outlook (Outlook 2010 SP2 or Outlook 2016) fail to login. If I create a new profile, I get endless prompts for credentials even though the user/pass is correct and the workstation is joined and logged into the domain.
Per this MS article:
Running this command: Restart-WebAppPool MSExchangeAutodiscoverAppP
ool immediate resolves the issue. The problem is, I have hundreds and hundreds of mailboxes to move and don't want to have to run the command for every move. I know that I can stage mailbox moves and complete many at once, but I'd like to get to the bottom of the issue if possible to have more flexibility.
In addition, as an alternative to running that command, I can build a new profile and make the user a domain admin. This resolves the continuous prompting and I can remove domain admin privileges immediately after the first login in. While this is not a viable option, it does lead me to believe that there is some form of permissions issue.
Is anyone aware of the root cause of this issue? I've reviewed countless articles regarding coexistence, failed mailbox moves, and checked, double checked and triple checked all of my DNS records, URLs, and virtual directory permissions. That said, I would be happy to check them again if anyone can zone in the best places to look.
Thanks a lot