Microsoft Exchange Server 2003

The arrival of Microsoft Exchange Server 2003 (ES2K3) is a significant event in the history of this product. First, it brings to a close the second era of the codebase. Released back in 1996 on the NT 4 wave, ES4 (there was no 1, 2, 3) brought enterprise-level email, contact management, diary management and so forth to the Windows Server platform in a new and comprehensive BackOffice application. The only comparable rival was Lotus Notes, and even then there were more differences than similarities between these two goliaths.

The first generation of Exchange Server lasted from ES4 to ES5 and thence to ES5.5, by which point it had also found a home within the Small Business Server 4.5 platform. By the final service pack of ES5.5, it had grown into a robust and capable platform that still does good work today for many companies. Note the phrase 'by the final service pack' - with ES, Microsoft has never shied away from adding useful new functionality in the service packs. Hence, service pack releases to Exchange Server have always been eagerly awaited to see what new tweaks were introduced.

With the arrival of ES2K, the second generation of the Exchange Server story emerged. This release required Windows 2000 Server and its new Active Directory infrastructure. For many, this was a leap too big to contemplate, which is why they're still on NT 4 and ES5.5. For those who made the move, there was a whole new raft of capabilities. Although the underlying storage engines weren't changed, there were improvements for the larger customers. Manageability and ease of use were considerably bettered too and, naturally, there were substantial improvements to the Outlook client as well. However, you had to understand Active Directory to make it work.

And now, with the arrival of ES2K3, the second wave is coming to an end. In all truthfulness, ES2K3 can be seen as a big service pack to the fundamental ES2K platform. Everywhere you look, there are improvements - manageability, performance, security, scalability and so on. But the major building blocks are the same. It will be the next big release of Exchange Server, probably ES2K6, before we see the beginning of the third wave of Exchange Server development.

To predict the changes this will bring, you need to understand that this is almost certainly the last large monolithic two-tier BackOffice application Microsoft will ever ship. Compared with the programming paradigms emerging from Redmond in Visual Studio, its XML work and the push to a new set of unified middle-tier application servers and services, ES2K3 is a big lumbering monster. The third generation will move Exchange Server into this new world order. So the storage will unify onto the forthcoming Yukon SQL Server engine and the WinFS underpinnings. The little-used and almost invisible Exchange Server Event Handling Engine will be replaced by Jupiter middleware components. And the whole thing will be rewritten in Common Runtime Language components. It's a major step to look forward to. But, in the meantime, we have ES2K3 and it's time to consider whether it's a good product, whether you should move to it and whether it's enough.

new features

Let's look at some of the new features in ES2K3. First, you should understand that this is probably the last chance there is for ES5.5 users to move forward in a controlled fashion. I have serious doubts as to whether Microsoft will support ES5.5 to ES2K6 in one step - you might have to do a dump right down to PST files to get data transferred. Plus, because primary support on ES5.5 is about to cease, you should be giving serious considerations to your upgrade routes from that platform now.