Choosing to Move to Exchange 2003

Moving to Exchange 2003 requires the same planning and discipline as moving to Windows 2003 outlined in the previous chapters. Exchange 2003 is a minor release architecturally, but a major functional release of the product. I like to think of the Exchange 2003 release as a refocusing of the product. Microsoft made Exchange 2000 sound as if it were all things to all people: a collaboration suite, an instant messaging platform, a "single store" (via the quickly killed "Web store" concept), and so on. Exchange 2003 is clearly an electronic messaging server. Electronic messaging is what brought Exchange to where it is today, and Microsoft has finally decided not to confuse the market by introducing nonmessaging related features into Exchange. Therefore, other products will be used to provide services such as collaboration and instant messaging.

The new features and functions in the product are major steps forward, though. The inclusion of mobility services (accessing Exchange from mobile devices such as PDAs and phones), the Recovery Storage Group (RSG), better SPAM and antivirus capabilities, messaging application programming interface (MAPI), access via Remote Procedure Calls (RPC) over HTTP(s), Virtual Snapshot Services (VSS), and the tightening of security throughout the product are major improvements. Other features include the even better Outlook Web Access, improved queue viewer, more intelligent link state routing, eight-node clustering in Enterprise Edition, the Microsoft Operations Manager (MOM) management pack, the ExDeploy tool (a step-by-step guide to upgrades), and the mailbox recovery center. All these features, both major and minor, are designed to make Exchange 2003 even more scalable and reliable than Exchange 2000. Already it should be clear that moving forward to Exchange 2003 just makes sense.

The migration and planning for Exchange 2003 can be done in parallel with the planning of Windows 2003. However, it's critical that your AD design along with your DNS implementation, are well thought out before deploying Exchange 2003. And remember, whereas Exchange 2003 can be deployed on both Windows 2000 SP3 and Windows 2003, Exchange 2000 will not run on Windows 2003 servers. So an upgrade to Windows 2003 of an Exchange server running on Windows 2000 will require an upgrade of Exchange first, and then the underlying operating system (OS). This is a change from past versions of the product, which required the OS to be upgraded first.

While we're on the topic of Exchange versions and OS versions, it's appropriate to present Table 12.1, describing the various combinations of the two.

Table 12.1. Exchange and Windows version matrix

Exchange/ OS Version matrix	Windows NT4.0	Windows 2000 in Windows 2000 Domain	Windows 2000 in Windows 2003 Domain	Windows 2003
Exchange 5.5 SP3	Yes	Yes	Yes	No
Exchange 2000 up to and incl. SP1	No	Yes	Yes	No
Exchange 2000 SP2	No	Yes	Yes	No
Exchange 2000 SP3	No	Yes	Yes	No
Exchange 2003	No	Yes	Yes	Yes

No matter where you stand today, if you are expecting to move to Exchange 2003, solid planning is required. Missing this key step is the downfall in many a deployment. Even worse , trying to fix a poorly planned migration and deployment is much more painful than the time and effort to plan things right up front. The work is fairly straightforward; figure out what you need to provide, figure out what you have, and determine how to get to the end-state.