TABLE OF CONTENTS Building a solid Windows infrastructure merely provides a robust platform for a new Exchange 2003 deployment. But what of the work required to evolve your existing Exchange 5.5 environments up to the brave new world that is Exchange 2003? Concerning ourselves with the Exchange 5.5 to Exchange 2003 migration aspect, this is not just an upgrade of a few binaries; this is the reengineering of a whole infrastructure. We're presented with almost myriad challenges: (1) providing mail coexistence between Exchange 5.5 and Exchange 2003; (2) providing synchronization services between the Exchange 5.5 and the AD; and (3) how to move Exchange 5.5 mailboxes to Exchange 2003 mailboxes. Of course, we haven't even mentioned Public Folder infrastructures, business applications built on top of Exchange 5.5, and other thirdparty products that may have potentially been integrated into your Exchange environment. And if that wasn't enough, we also need to be concerned with the effort that's required to upgrade the underlying infrastructure that Exchange 2003 will run on. In all likelihood, you'll probably have Windows NT4 deployed for account domains and resource domains for Exchange 5.5 servers, and these domains will need to be upgraded to Windows 2000 or Windows 2003.
As you can see, moving up to Exchange 2003 isn't just about upgrading a single software product: It's about building a new infrastructure and doing so in a smooth and transparent way so that none of your existing users has an interruption to service. It's not impossible to do, and...
