Today, after restarting Exchange Server 2013, the Outlook client did not connect to Exchange Server.
So, we check the event viewer and we found the following error:
Event Id 15021
An error occurred while using SSL configuration for endpoint 0.0.0.0:444. The error status code is contained within the returned data.
So, to solve this, just enter IIS, Exchange Back End, Bindings, select https 444 edit, select the valid certificate, ok.
Ok, see in the Event Viewer, find to Event ID 15301
If you need, iisreset /noforce.
Credit to Eliezer Nunes