System Attendant on Front-End Servers

System Attendant on Front-End Servers

By default, Exchange System Attendant no longer requires RPCs when it runs on a front-end server. The components of System Attendant that use RPCs are no longer loaded on front-end servers; therefore, these components are disabled when you designate a server as a front-end server. The following list briefly describes these components:
DSProxy The DSProxy service refers MAPI clients (such as Microsoft® Office Outlook® 2002) to global catalog servers for global address list lookups. DSProxy also allows MAPI clients with older versions of Outlook to access Active Directory. DSProxy no longer runs on front-end servers; therefore, the front-end server can no longer determine which back-end server contains a MAPI client's mailbox. As a result, you cannot point a MAPI client to the front-end server to determine the user's back-end server and then route the request to the appropriate server.
Note:
To enable DSProxy on the front-end server for routing MAPI client requests, install Exchange 2000 Server Service Pack 3 (SP3) and create the registry key described in Microsoft Knowledge Base article 319175, "XADM: You Cannot Perform a Check Names Query Against a Front-End Exchange Computer." Note that to receive these referrals, the client must have RPC access to the front-end server. Additionally, the front-end server must have RPC access to domain controllers.
Recipient Update Service The Recipient Update Service updates recipients in the directory to match address lists or recipient proxy policies. The Recipient Update Service no longer runs on front-end servers, so be sure that none of your front-end servers are designated to run the Recipient Update Service. To do this, in Exchange System Manager, under Recipients, check the properties of each Recipient Update Service and ensure that no front-end servers are named in the Exchange server field.
Offline Address Book Generation (OABGen) OABGen creates the offline address book. Without the OABGen service, front-end servers no longer generate offline address books.
Group Polling System Attendant uses group polling to ensure that the local computer remains a member of the Domain Exchange Servers group. System Attendant polls the Domain Exchange Servers group and adds the local computer back to the group if it is no longer a member. Front-end servers no longer perform this function.
Mailbox Management The Mailbox Management service starts and stops the mailbox cleanup process according to the settings defined in Recipient Policies. Mailbox Management no longer runs on front-end servers.
Free/Busy (madfb.dll) The free/busy service manages user schedules. This service no longer runs on front-end servers.