User Configuration > Administrative Templates > Microsoft Outlook 2016 > Account Settings > Exchange
User
HKCU\software\policies\microsoft\office\16.0\outlook\autodiscover
This policy setting determines whether Outlook can interact with the Office Config Service to get Autodiscover V2 service endpoint URL for different sovereigns. if you enable this policy setting, Outlook will get the URL for the sovereign Autodiscover v2 service endpoint by default. If you disable this policy setting, Outlook will get the URL for the WW Autodiscover v2 service endpoint by default.