Nothing is ever easy in life, and that is especially true when you talk about going from one version of a Microsoft server to another. Exchange 2000 is no exception. Exchange 5.5 used its own directory service, but Exchange 2000 uses Active Directory for its directory services. This is likely more efficient, but it can cause a problem while you're in the process of upgrading from 5.5 to 2000.
When you migrate to Exchange 2000, you will find that you will be using Active Directory for Exchange Services. Now that's probably great, because Active Directory is a great directory service, and with it, the directory service for Exchange will be integrated with directory services for the overall operating system for your enterprise.
But Exchange 5.5 doesn't do that. It uses its own directory service. So what that means is that you have to have some way to connect the directory service of Exchange 5.5 to Active Directory, for as long as you are going to run Exchange 5.5 with Active Directory. That means you will have to synchronize the directory service of 5.5 with Active Directory. Fortunately, Microsoft has an Active Directory connector in its Exchange 2000 Server, so you have the tools to accomplish this task.
The company has an instruction manual on its Web site that tells you how to go about this. It's a portion of the overall planning guide for upgrading to/installing Exchange 2000. If you haven't upgraded yet, or are wondering if you should, or are thinking of leaving some other mail system and migrating to Exchange, you should probably check this out.
David Gabel is Executive Technology Editor of TechTarget.