I do not have Outlook, so the only way I can think to test this is via https://testconnectivity.microsoft.com
When I tried it, I get an error:
Testing HTTP Authentication Methods for URL https://mail.example.com/Microsoft-Server-ActiveSync/.
The HTTP authentication test failed.
Code: Select all
A 401 error was received from the server, but no authentication methods are supported.
HTTP Response Headers:
Public: OPTIONS, POST
Allow: OPTIONS, POST
Date: Wed, 18 Oct 2017 15:02:28 GMT
WWW-Authenticate: BASIC realm="Zimbra"
Elapsed Time: 768 ms.
How can debug and fix this issue? Is it related to the fact that autodiscover (incorrectly) thinks it's on port 8443?