Hello; If we summarize the differences between Exchange Server 2007 and Exchange Server 2010 under short headings; •Exchange Server can be used on its own or Exchange Online •Database portability has arrived in High Availability (HA) solutions –Database availability group (DAG) and database copy feature is here –Site resilience and disaster recovery –30 seconds switchover/failover –Storagesupport (Serial Analog Terminal Adapter (SATA) disks, JBOD (Just a Bunch of Disks) configurations become supported) –Standby continuous replication (SCR), local continuous replication (LCR), single copy cluster (SCC) and cluster continuous replication (CCR) discontinued in Exchange Server 2010 •Management Tools are 64-bit only •Remote procedure call (RPC) Client Access and Address Book services –High Availabi lity solutions have been developed: Outlook MAPI connects directly to Client Access Servers and performs mailbox and directory operations ExOLEDB, WebDAV and CDOEx is gone –“Entourage EWS” Uses Exchange Web Services