What to Do Next

As with most upgrade decisions, if an organization’s current Exchange solution fulfills all existing and anticipated needs, there is generally no reason to upgrade. However, because NT 4.0 and Exchange 5.5 are nearing their end-of-life in terms of Microsoft support, the increasing obsolescence of these products could present difficulties and obstacles, such as new security vulnerabilities and incompatibility with newer hardware and software products.

Organizations on Exchange 5.5 (nearly half of all Exchange servers are still running this version) cannot upgrade those servers in-place to Exchange 2003. Instead, they must build new Exchange 2003 servers and move existing mailboxes and public folders onto them. Although many organizations will use the migration as an opportunity to upgrade their Exchange server hardware and possibly to consolidate servers, other organizations will see this as a step back from Exchange 2000’s migration path, which supports in-place upgrades.

However, customers already on Exchange 2000 can perform in-place upgrades relatively painlessly, and Exchange 2000 and 2003 servers can readily coexist in an Exchange system, so organizations can upgrade gradually.