Microsoft developed Exchange 2010 as a service first,

In a year in which many Office 2007 download businesses--including a number within Microsoft--took a hit, the Exchange business continued to grow last year, Jha said, saying that revenue for the product nearly hit $2 billion and has 70 percent market share among corporate users.

Jha acknowledged, though, that competition for the in-box is definitely heating up.

"It is where people spend more of their hours," Jha said. "It's become a real critical part of the day. Our competitors are smart. They see it too."

In addition to Google, IBM continues to push its Lotus Domino/Notes combination while Cisco has said it will have a Linux-based e-mail offering based on last year's Postpath acquisition.

Sounding a familiar refrain, Jha said that he expects customers to warm to Microsoft's strategy, which lets them have the option of running Exchange themselves or purchasing it as a subscription hosted service.

"With Exchange, we don't give them any kind of technology ultimatum," Jha said. "We don't say 'Thou shalt move to the cloud.' "

Microsoft has shifted its priorities, though. Unlike past versions of Exchange, Microsoft developed Exchange 2010 as a service first, and only later has it done the work on the server product. That server product, which has been in testing for some time and reached the beta stage in April, is now ready in a near-final "release candidate" form.

Among its features is one that lets users "mute" an e-mail thread that they are no longer interested in being part of.

Jha reiterated that the final version of Office 2007 should be done later this year.

"I feel pretty good about how we are tracking," he said, noting that half of Microsoft Office Ultimate 2007 in-boxes--some 80,000--are now on the new version of Exchange. " We'll definitely be ready this year."