Exchange 2010 co-existence with Exchange 2016

[XistEnCe]

Hello everyone!

 

I've setup a co-exist environment with Exchange 2010 and Exchange 2016.

At the moment mail-flow seems to work with no problems what so ever, and I have migrated two test-users from 2010 to 2016.

 

SMTP traffic and HTTPS is proxied from the new Exchange 2016 installation - and works fine for the 2010 users behind.

 

My problem is that when the users are migrated, outlook 2016 is having issues connecting to the new server.

When I open outlook, it still uses RPC/HTTP towards the old server.

If I delete the old profile, and re-create it using autodiscover, it works fine.

I then see MAPI traffic and it hits the new server as expected.

 

This would cause a problem if I manually have to re-create profiles for all the users in our company..

Does anyone have any pointers?

 

 

[XistEnCe]

Not completely sure what actually did the trick.

We checked all the virtual-directories and confirmed both internal and external was set correctly.

The auth was also changed to NTLM for OutlookAnywhere (Get-OutlookAnywhere); and we restarted IIS.

 

We still have a bug where it seems to reset the internal URL every now and then, but an IIS reset will fix it.

It is still not known why.