Last week I moved a client from a single Windows Small Business Server 2008 setup to a Windows Server 2016 setup using Hyper-V. The new setup is 1 physical server with a handful of virtual machines broken out for different roles. Part of this migration was a new domain and a new Exchange server. The Exchange 2016 based setup worked without a problem until I was dealing with a remote user. The remote user is not on the domain but has a router to router VPN back to the main location. When trying to change their Outlook over to the new Exchange server I kept getting errors about a MAPI timeout. I tested and could ping the Exchange server by IP, name, FQDN, and even external address. Typically when changing a user’s Outlook from one system to another I just create a new Outlook profile so I can keep their old one as a backup just incase. After continuing to get the MAPI timeout errors I gave in and decided to blow out all their old Outlook profiles. No go. They had 3 Outlook profiles and when trying to delete any of them I would get the error: The action could not be completed because the action could not be completed. Not a very helpful error but it did confirm I had issues with the old profiles. I ended up deleting the profiles via the registry then guess what? The new Outlook profile worked without a hitch.