When you install Exchange 2000 Server or Exchange Server 2003 on a domain controller remember that:
– the domain controller must not be a node in a server cluster (Microsoft do not support Exchange 2000 Server clusters or Exchange Server 2003 clusters that are configured on Active Directory domain controllers)
– the installation of Exchange on a domain controller may affect the performance of that domain controller
– the domain controller that is running Exchange must also be a global catalog Server
– a malicious user could try to elevate their permissions in Active Directory directory sernice
– the domain controller may take 10 minutes or more to shut down