Microsoft now dominates the enterprise collaboration market, although it wears that crown uneasily. The vendor seems more nervous than ever about its future prospects in the  collaboration market - and it has many good reasons to worry.

Microsoft is locked into a long-running horse race with Lotus for the lead in the groupware arena, and any slip on its part could jeopardize its market standing. Microsoft also recognizes the challenges it faces from standards-based messaging products, browser-based Web collaboration products and peer-to-peer offerings, as well as such competitors as Lotus and Novell.

Microsoft has the undivided attention of competitors, most of which aren't shy about pitching their collaboration products as alternatives to Exchange. Dozens of vendors can claim that their products do the core of what Exchange does - e-mail and calendaring/scheduling - and can do it less expensively.

On the customer side of the equation, Microsoft is painfully aware that no more than one-quarter of its Exchange 5.5 installed base has upgraded to Exchange 2000, in spite of that latter version's having been on the market for more than two years. Users' beefs with Exchange 5.5 and Outlook include the products' premium pricing, performance and scalability problems; substandard offline access functionality; inflexible public folders; and vulnerability to viruses and spam.

Microsoft must know that many corporate customers are looking for alternatives to Exchange 2000. There's nothing particularly wrong with Exchange 2000, and it adds considerable new user and administrative functionality over Exchange 5.5. But upgrading to Exchange 2000 requires a concurrent upgrade to Windows 2000 and Active Directory. Many Exchange users are reluctant to undertake three concurrent infrastructure upgrade projects when IT budgets are under serious pressure from a down economy. Many organizations will look seriously at any standards-based product that does e-mail and calendaring as well as Exchange.

But there's little evidence that established Exchange users are migrating from Microsoft's collaboration offering in great numbers. Nevertheless, Microsoft has developed a defensive strategy that primarily revolves around an aggressive offense. Undeterred by sluggish customer acceptance of Exchange 2000, Microsoft has pushed the development of the next two versions of the product, code-named  Titanium and Kodiak (slated for release in 2003 and 2004-2005, respectively). Once again, Microsoft is announcing impressive feature lists and promising significant improvements in user and administrator productivity.