This chapter discussed the processes to follow to coexist with and upgrade from Exchange 2000 Server to Exchange Server 2003. Unlike the complicated path and procedures involved when coexisting with and migrating from Exchange Server 5.5, the coexistence with Exchange 2000 Server is made easy by the familiar interface, similar services, and the fact that user accounts already exist as Active Directory objects.
Before you can install an Exchange Server 2003 server into an existing Exchange 2000 Server organization, all Windows 2000 Servers and Exchange 2000 Servers should be at Service Pack 3 or later. This requirement is also true when upgrading an Exchange 2000 Server computer directly to Exchange Server 2003. Exchange 2000 Server does not run on Windows Server 2003, so you must perform an upgrade to Exchange Server 2003 first and then to Windows Server 2003.
Several components that you may have gotten used to using in Exchange 2000 Server are no longer supported in Exchange Server 2003. Before you upgrade or decommission the last Exchange 2000 Server, ensure that you no longer need the following components in your Exchange organization:
Microsoft Mobile Information Server
Instant Messaging
Exchange Chat
Exchange 2000 Conferencing Server
Key Management Service
The cc:Mail connector
The MS Mail connector