10-16-2018 07:12 AM
My first thought when reading this is autodiscover.
It sounds like it may be a DNS issue with your autodisocver record (that would be my first check).
Have you tried manually setting up your outlook profile to point at your old exchange server rather than an automated setup?
To get a better idea outside of that, run some tests at https://testconnectivity.microsoft.com/
I would recommend the outlook connectivity and outlook autodiscover. For you it should be under exchange server, but with the issue you are having I would be interested what the O365 test returned as well.
Those test should give us more details.
10-16-2018 07:32 AM
Ya it sounds like something with routing/DNS that is causing the issues in the newer versions.
Can you give the testconnectivity.microsoft.com test a few runs and see what errors you get?
10-16-2018 10:50 AM
First of all, definitely contact your hosting provider support, as there might be an issue on their side, or they might have introduced some changes. Next, can you provide some screens or output from the autodiscover test in Outlook?
If you are using O365 and have an account there, what might happen is that Outlook tries to "connect to O365 as priority", which is a behavior you can control via the reg keys detailed here: https://support.microsoft.com/en-us/help/3211279/outlook-2016-implementation-of-autodiscover
This step is only available on 2016, so might as well explain why 2010 works fine.