Disable ADAL for Outlook 2016

Problem

Various authentication issues including:

• O365 profiles sets up instead of on prem mailbox
• Outlook wont authenticate on Office 365
• Outlook wont authenticate on Office 365 with SSO

Cause

ADAL is the new authentication method for azure cloud solutions. It over-rides the standard kerberos, basic and NTLM protocols.

Solution

ADAL can be disabled by registry key:

To disable modern authentication on a device, set the following registry keys:

Reference, Links and Imges

https://answers.microsoft.com/en-us/msoffice/forum/msoffice_outlook/modern-authentication-on-outlook-2016-keeps-on/98a263f4-ab9c-4d6f-b5eb-2728a8e77412