Windows Registry Editor Version 5.00 

[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover] 
"ExcludeHttpsRootDomain"=dword:00000001 
"ExcludeExplicitO365Endpoint"=dword:00000001 

[HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\office\16.0\outlook\autodiscover] 
"ExcludeExplicitO365Endpoint"=dword:00000001