A component that is not represented in Active Directory is the UM Web Services. This is a web service that is installed on Exchange 2010 servers that have the Client Access role.
The service is used for the following:
• Play on Phone feature for both Outlook 2010 and Exchange 2010 Outlook Web App
• PIN Reset feature in Exchange 2010 Outlook Web App
This service requires that at least one Exchange 2010 server run the Client Access, Hub Transport, and Mailbox Server roles in addition to the Unified Messaging role.