For maximum coexistence flexibility, you can install an Exchange
2000 server in an existing Exchange 5.x site. This feature
allows organization with earlier versions of Exchange clients and
servers to take advantage of new Exchange features without
upgrading the entire installation. When adding an Exchange 2000
server to a mixed-mode topology, you need to create a new
When Exchange 5.x servers and Exchange 2000 servers
communicate within the same site, they use only
All intra-site directory replication between Exchange 5.x
and Exchange 2000 occurs through the