SAN FRANCISCO (10/10/2003) - In my book, there are two kinds of upgrades: the unnoticed and the long-remembered. With the first kind, no one notices that there's an upgrade in process. The second is a lot more dramatic, and while the long-term benefits of such a process may be easily defined, the pain is all anyone remembers.
Migrating an Exchange 5.5 organization to Exchange 2003 falls into the second category: the painful, shot-of-whiskey-and-a-bullet-to-chew-on upgrade. If management wants to make full use of the Exchange features, IT staff and end-users will have so many tasks that they'll swear they're moving to a completely different platform. In many respects, they are.
An IT staff can't perform an in-place upgrade from Microsoft Corp. Exchange 5.5 to Exchange 2003 while using the same server hardware and OS configuration; the installer simply won't do it. It's theoretically possible to take a server that's running Exchange 5.5, upgrade it in-place to Exchange 2000 (which involves a Windows upgrade as well -- only then can Exchange be upgraded), and follow with an in-place move to Exchange 2003. But why anyone would choose to go through that kind of agony is beyond me. For once, it actually is easier to follow the directions.
Much of the remaining pain stems from the migration of user information from the traditional Exchange user directory into Microsoft's AD service. Although it's true that the two can coexist to a degree -- AD can present itself as an old-style Windows NT domain structure, and NT's user domain system was filched from Exchange in the first place -- sites moving from Exchange 5.5 to Exchange 2003 face the same challenges involved in a move to Exchange 2000, but with tools barely improved since the release of Exchange 2000.
If a new Exchange organization has to be set up, the list of items that can't be easily moved from an Exchange 5.5 server to one based on Exchange 2003 is still staggering. About all users can expect to salvage is their mailbox content. Inbox rules, public folders, out-of-office messages, offline folders and address books, personal address books, and encryption and signature features won't make the trip. Only a squeaky-clean Exchange 5.5 setup stands a chance of anything less painful.