Exchange 2007 Services and Function
Microsoft Exchange Active Directory Topology/MSExchangeADTopology
Provides Exchange Server 2007 with Active Directory site, domain controller, and global catalog server information. This component is found on all Exchange 2007 server roles except the Edge Transport
Microsoft Exchange ADAM/ADAM_MSExchange
This is the ADAM instance that holds the Edge Transport server role's configuration, recipient information, safe sender lists, and blocked sender lists. This service is only found on the Edge Transport role.
Microsoft Exchange Anti-spam Update/MSExchange AntispamUpdate
This service provides updates for the content filter service. This service is found on the Edge Transport and Hub Transport server roles.
Microsoft Exchange Credential Service/EdgeCredentialSvc
This service monitors credential changes for the ADAM database and updates the Edge Transport server. This service is found only on the Edge Transport server role.
Microsoft Exchange EdgeSync/MSExchangeEdgeSync
Handles synchronization of recipient and hub transport information to Edge Transport servers in the perimeter network. The EdgeSync process synchronizes to the Edge Transport server's ADAM database; the synchronization is a push synchronization from the Hub Transport role out to the Edge Transport server. This component is found on Exchange 2007 Hub Transport server roles.
Microsoft Exchange File Distribution/MSExchangeFDS
The File Distribution Service handles distribution of offline address books on Client Access servers and custom Unified Messaging prompts on UM servers. It is found on Exchange 2007 Client Access and Unified Messaging server roles.
Microsoft Exchange IMAP4/MSExchangeIMAP4
Provides IMAP4 client connectivity and is found on Exchange 2007 Client Access server roles. This service is set to manual by default and must be enabled to support IMAP4 clients.
Microsoft Exchange Information Store/MSExchangeIS
The information store service runs the database engine and provides client access for MAPI clients as well as access to mailboxes for connections from Client Access and Hub Transport servers. This service is only found on Exchange 2007 servers with the Mailbox server role. This service also consumes the most RAM of any of the Exchange 2007 services.
Microsoft Exchange Mail Submission Service/MSExchangeMail Submission
Handles notifying Hub Transport servers that a message is waiting to be retrieved from a local database. This service attempts to distribute the message delivery load if multiple Hub Transport servers are found. This service is found on the Exchange 2007 Mailbox server role.
Microsoft Exchange Mailbox Assistants/MSExchangeMailbox Assistants
The Mailbox Assistants service handles calendaring functionality such as Calendar Assistant, Resource Booking Assistant, Out-of-Office Assistant, and the Managed Folder Mailbox Assistant. This service is found only on Exchange 2007 Mailbox servers.
Microsoft Exchange Monitoring/MSExchangeMonitoring
Provides an interface for applications to use Exchange 2007 monitoring tasks. This service is found on all Exchange 2007 server roles.
Microsoft Exchange POP3/MSExchangePOP3
Provides POP3 client connectivity and is found on Exchange 2007 Client Access server roles. This service is set to manual by default and must be enabled to support POP3 clients.
Microsoft Exchange Replication Service/MSExchangeRepl
This service handles copying log files from their original location to the backup log location on Exchange 2007 Mailbox servers that have the local continuous replication or clustered continuous replication functions enabled. This service is found only on Exchange 2007 Mailbox server roles.
Microsoft Exchange Search Indexer/MSExchangeSearch
The Microsoft Exchange Search Indexer provides content to the Microsoft Search (Exchange Server) service for full-text indexing. This service is found only on Mailbox server roles
Microsoft Exchange Service Host/MSExchangeServiceHost
This service handles the configuration of RPC virtual directories and Registry information necessary to support Outlook Anywhere (RPC over HTTP). This service is found on Exchange Mailbox and Client Access server roles.
Microsoft Exchange Speech Engine/MSS
The Speech Engine service provides the speech processing capabilities that are used by Unified Messaging services. This service is found only on Unified Messaging server roles.
Microsoft Exchange System Attendant/MSExchangeSA
This service provides monitoring and directory lookup services for Exchange server. This service is found only on Mailbox server roles.
Microsoft Exchange Transport/MSExchangeTransport
This service provides the SMTP transport functions. Mail will not flow at all if this service is halted. This service is found on all Exchange 2007 Hub Transport and Edge Transport server roles.
Microsoft Exchange Transport Log Search/MSExchangeTransport LogSearch
Provides the ability to search the Exchange message transport logs. This service is found on all Exchange 2007 Mailbox, Hub Transport, and Edge Transport server roles.
Microsoft Exchange Unified Messaging/MSExchangeUM
The Unified Messaging service handles access to user's mailbox via Outlook Voice Access, the creation of voicemail messages, and the creation of fax messages. This service is found only on the Unified Messaging server role.
Microsoft Search (Exchange)/MSFTESQL-Exchange
This Search service creates full-text indexes on mailbox content. This service is found only on the Exchange 2007 Mailbox server role.
World Wide Web Publishing Service
A component of Internet Information Services that is required on all Exchange 2007 Client Access server roles in order to provide access to web services. This service is required on Exchange 2007 Mailbox servers if you will be managing public folders using Exchange System Manager or PFDAVAdmin.
Small Business Server 2008 Note:
We have 17 Services related to exchange, out of which only 12 of them should be running on SBS 2008 Server
-Microsoft Exchange Active Directory Topology Service
-Microsoft Exchange Anti-spam Update
-Microsoft Exchange File Distribution
-Microsoft Exchange Information Store
-Microsoft Exchange Mail Submission
-Microsoft Exchange Mailbox Assistants
-Microsoft Exchange Replication Service
-Microsoft Exchange Search Indexer
-Microsoft Exchange Service Host
-Microsoft Exchange System Attendant
-Microsoft Exchange Transport
-Microsoft Exchange Transport Log Search