I completed a 2010 to 2016 migration and was having some issues with outlook clients connecting externally if they had not be opened up internally after the migration. In my drug fueled haze while getting over the flu, I thought it was a good idea to remove the 2010 server out of the equation as I thought it was what was cause the issue so I complete the migration, removed the old OAB, migrated all the mailboxes including arbittration and uninstalled the 2010 server.
All DNS is setup pointing to new exchange server including the old 2010 server name. And now internal clients cannot open outlook because there is no 2010 server to let them know their profile has been moved to the 2016 server(atleast this is what I'm guessing the issue is).
Deleting the profile and recreating it fixes the issue; however, that's not feasible for the 1000 users I'll have showing up on Monday trying to access their outlook.
Is there something I'm missing here? Am I SOL without the old 2010 server still around for them to proxy over to 2016?
Most outlook clients are either the latest version of 2010 or 2016