AutoDiscover request failed due unauthorized HTTP response

Overview

When you see the message AutoDiscover request failed due unauthorized HTTP response while trying to connect the profile to your external calendar you need to use the advanced settings to fix this. 

This way you can manually override the Exchange Web Services and the Offline Address Book URLs.

How to

• Go to Manage Profile > Configure Systems
• Click on Show Settings in the Advanced Settings section
• Set the Use Autodiscover option to No
• Fill in the EWS and OAB URLs and Save

How to retrieve the EWS and OAB URL is explained in this article