In our case the solution was as follows:
“In case anyone runs into the issue that our company had, a registry key was set on the server blocking older Outlook clients access to the exchange server (HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem) Disable MAPI Clients = -10.0.0. The EMSMDB32.dll file which is installed with the MAPI Client and Collaboration Data Objects 1.2.1 is at version 6.5.8244.0 which was blocked by the key. More info can be found here:
I'm having the same issue. Were you able to figure it out?