What is it?
Exchange Server is software run on a server that enables you to send and receive e- mail and other forms of interactive communication through computer networks. Designed to interoperate with a software client application such as Microsoft Outlook, Exchange Server also interoperates with Outlook Express and other e-mail client applications.
In the summer of 2005, computer resellers launched a marketing push to convince users of the business benefits of moving to Exchange Server 2003.
For all the arguments, a lot of users saw no benefits to justify the expense and disruption of upgrading. With support for 5.5 finishing at the end of 2005, the case was becoming urgent - but for many otherwise happy users, the withdrawal of support was the only reason to move.
Towards the end of 2005 Microsoft released betas of Exchange 12, due to ship in late 2006 or early 2007. This will put a much wider gulf between users as the latest version runs only on 64-bit.
Where did it originate?
The Exchange Client was part of Windows 95. Exchange Server 4.0 was released in 1996.
What's it for?
As well as messaging, Exchange offers calendar/diary applications, the one remnant of its original role as a collaboration hub. The collaboration role has now been embedded in other applications such as Office and Sharepoint.
What makes it special?
Exchange Server 2003 and subsequent service packs provide a high - though far from infallible - level of virus and spam protection, and good disaster recovery when that protection fails. Supported database sizes have been progressively increased, and integration both with Microsoft's own applications and third-party messaging products improved. At the same time, some functions, such as conferencing, which used to be part of Exchange have been split off as applications in their own right.
Exchange 12 promises more control for users and administrators through simplified interfaces, and greatly improved spam and virus protection. As for the move to 64-bit, Microsoft said, "We heard from our customers that their current messaging solutions were being pushed to the limit." However, more than 50% of users have not yet migrated to Exchange Server 2003.
How difficult is it to master?
Becoming a Microsoft certified systems administrator (MCSA) messaging specialist involves three core and one specialist exam, requiring up to 23 days of training.
What's coming up?
Gartner said the move to 64-bit would make migration "slower and more complex", requiring mixed Exchange 2000/2003 and Exchange 12 topologies at first, but the performance improvements would justify any migration problems.
Microsoft's Gold Certified Technical Education Centres offer a two-day course to get you from Exchange Server 5.5 or 2000 to 2003. You can get the Exchange 12 Community Technology Preview by signing up to Microsoft's Technet.
Rates of pay
Exchange administrators can earn £20,000 to £35,000, with higher rates for architects and infrastructure engineers.