Microsoft also thinks it has an advantage because it pledges to keep the code bases for the on-premises and cloud-based services the same, even if features show up in one place before the other. However, the ability to continuously innovate is one of the strengths of the cloud, says Schadler. Given that and the rapid pace of change in Google Apps, it's hard to imagine Microsoft holding off on introducing innovative new features online until major versions of Exchange software are released.
In fact, Microsoft is already tweaking its online product, making changes and adding some new features every 45 days. "As we move forward, you'll see new things show up on our [online] service first, because we can. When the new [on-premises] version comes out, you'll see them show up on the server," White says. But, she says in a dig at Google, "we don't take a consumer-oriented approach [for enterprise use] and just roll things out [untested]."
While Google and Microsoft prepare for battle, it's still very much early days for cloud-based e-mail in the enterprise. For most organizations, it's not about whether Microsoft or Google is better, but whether to move into the cloud at all.
"Microsoft would like to believe everyone is talking about putting e-mail in the cloud, but ... nobody is rushing to do it just yet," says Sara Radicati, president and CEO of The Radicati Group, a market research firm. Indeed, so far Microsoft has just a handful of enterprise customers using its online offering. "The vast majority are businesses with 5,000 users or less," she says. Mass adoption among large businesses, if and when it comes, is likely to roll out very slowly, she predicts.
Robert L. Mitchell writes technology-focused features for Computerworld. You can follow Rob on Twitter at http://twitter.com/rmitch, send him e-mail at email@example.com or subscribe to his RSS feed.
John Brandon contributed to this story