Found this recently while setting up a Hosted Exchange account, where autodiscover was configured with an SRV record but no XML or other newer methods. Outlook was taking forever to finish “searching for account settings”, and google helped me with the following reg key to prevent Outlook from retrying the first methods over and over – and just go on to the next!

Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover]
“ExcludeHttpsRootDomain”=dword:00000001

All good – account setup took a couple of seconds after that!