Exchange 2007 main Services:

Microsoft Exchange Active Directory Topology 

Microsoft Exchange Monitoring

Microsoft Exchange IMAP4

Microsoft Exchange POP3

Microsoft Exchange Transport Log Search

Microsoft Exchange Transport: On Hub and Edge

Microsoft Exchange Service Host

Microsoft Exchange Search Indexer

Microsoft Exchange Replication Service

Microsoft Exchange Mail Submission

Microsoft Exchange Mailbox Assistants

Microsoft Exchange File Distribution: On CAS Server

Microsoft Exchange Information Store

Microsoft Exchange System Attendant 

Microsoft Exchange EdgeSync: on Hub Transport Server

Microsoft Exchange Anti-spam Update