In Exchange 2000, Windows 2000 Active
Directory replaces the Exchange 5.5 directory service.
All directory information regarding Exchange recipient and
configuration objects resides in Active Directory instead of in
separate directories for Exchange and Windows objects. When your
messaging system includes connections to previous versions of
Exchange, you must ensure that your existing Exchange 5.5 directory
service is synchronized with Active Directory by using Active Directory Connector (ADC). Proper
synchronization between Exchange 2000 and Active Directory ensures
that your Exchange messaging system functions reliably.
You may experience specific problems when managing connections
to previous versions of Exchange; for example, you may need to
resolve directory synchronization problems by monitoring the events
that occur when replicating objects between directories.
To identify and resolve specific problems that can occur with
Active Directory, see Common Issues.
To learn more about ADC and coexisting with previous versions of
Exchange: