Jeff Ressler, the director of product planning for Microsoft Exchange, in Redmond, Wash., told eWEEK in an interview this week that Exchange was the market leader whose share was growing.
"We still worry more about Lotus than about the open-source providers, a lot of whom dont have a unified strategy [for trying] to try and address the bigger players in the market. There are interesting things happening with some of them, but they dont come up often in our competitive engagements," he said.
In fact, many of Exchanges open-source competitors are introducing Web interfaces that are trying to emulate the functionality Microsoft has already had in Outlook Web Access for a number of years, he said.
Reaction from competitors in both the proprietary and open-source space was quick and dismissive of those claims.
Simon Phipps, Sun Microsystems Inc.s chief officer of open source, said Suns Internet Mail Server is more advanced than Exchange and is the mail server of choice for many large enterprises. "Numerically, we service more e-mail accounts than they do," he said.
Julie Hanna Farris, the founder and chief strategy officer of Scalix Corp., a messaging infrastructure company based in San Mateo, Calif., whose products are based on a Linux and open systems architecture, questioned exactly what "unified strategy" meant.
"Microsofts approach is to give customers an integrated stack, and that is what some customers want. But there is another category of customers that wants the flexibility to create their own stack and customize their ecosystem based on their choice of best of breed components, like choice of directory, for example," she said.
Much of the debate about lock-in was about exactly that, she said, adding that giving customers the flexibility to choose did not mean they had to sacrifice a unified approach to their e-mail environment.
With regard to the comments by Microsofts Ressler that open-source solutions did not come up often in competitive engagements, Farris said more than half of Scalixs customers had switched from Exchange to Scalix, while the other half had switched from a combination of Lotus Notes/Domino, Novell GroupWise and SendMail.
But Microsoft is working hard to make sure that Exchange 12 appeals to both enterprise IT administrators and end users.
The first beta of the product, which was released to a small, private group of some 1,400 testers earlier this month, offers enhanced administrative controls as well as a unified messaging feature that will deliver fax, voice mail, e-mail and speech recognition.
But some competitors, like officials at Sun and Scalix, pointed out that many of those "new" features are available in other, existing products today and that Microsoft was playing catch-up in this regard.
Tim Bray, a Sun Web technologist and the co-inventor of XML, told eWEEK that while some of Microsofts software was excellent, "I cannot say that Exchange falls into that category," whether from a technical engineering or feature-set perspective.