Microsoft released the latest version of its Exchange e-mail server Monday with claims that Exchange 2010 could cost as much as 70% less than previous versions in terms of total cost of ownership.

The move comes just a week after Microsoft slashed the price of its online productivity suite, which includes a cloud-based version of Exchange, from $15 per user to $10 per user.

Cost has become a big topic in the e-mail world, as last month IBM announced it was releasing its own e-mail service, Lotus iNotes, for $3 per user, and as Google recently won a highly-publicized bid to become the city of Los Angeles' e-mail provider at one third the price of Microsoft's bid.

Though Exchange remains by far the dominant corporate e-mail platform, Google continues to get notice while competitors continue to ply their hands at the corporate market. In addition to IBM's announcement of a SaaS version of Notes, Cisco announced Monday that it would be entering the corporate e-mail market by integrating e-mail capabilities into its WebEx collaboration suite.

In an interview, however, Microsoft business division president Stephen Elop didn't sound worried. He said that the largest pool of new customers for Exchange Online continues to come from Notes, that people "quickly see through the marketing and PR hype" of Google, and that he challenged "the premise that [Cisco] has integrated real corporate e-mail."

Microsoft isn’t cutting the price of its on-premises server, which lists at $699 for the standard edition and $3,999 for the enterprise edition, and $67 and $35 per client access license, respectively. Instead, Elop said, most of the savings will come from a combination of new features in Exchange 2010 and the slow migration to e-mail as a service.

Forrester Consulting released a study Monday, commissioned by Microsoft, indicating a payback period of just six months for Exchange 2010.

In terms of new features in Exchange 2010, Elop attributed the cost savings to a "simplified high-availability model and support for lower-cost storage" as well as native archiving and new features that allow customers to replace their voicemail infrastructure with Exchange.