Answer:
The Autodiscover service gathers the required configuration information in Active Directory to enable Outlook 2007, Office Outlook Web Access, and mobile e-mail clients to efficiently locate and connect to the appropriate Exchange 2007 Mailbox server that contains the user's mailbox. The Autodiscover service is also used to make configuring Outlook 2007 clients easier and to provision mobile devices that are used to connect to Exchange 2007. By default, the Autodiscover service is enabled.