An Autodiscover record enables %BRAND_OUTLOOK_SHORT% (Outlook 2007 and later) and mobile clients to connect automatically ...

An Autodiscover record enables %BRAND_OUTLOOK_SHORT% (Outlook 2007 and later) and mobile clients to connect automatically to your %BRAND_OFFICE_365_SHORT% mailboxes. Your Autodiscover record should continue to point to your on-premises %BRAND_EXCHANGE_ONLINE_SHORT% server until you decide to decommission your on-premises %BRAND_EXCHANGE_ONLINE_SHORT% infrastructure.