Microsoft last week said Exchange 2007 will include a new client-access license option geared to corporate users and that Beta 2 of the server will include new e-mail hygiene, compliance, replication and data-protection features.

Microsoft said it plans to ship Beta 2 of Exchange Server 2007 this summer with final release slated for late 2006 or early 2007.

"The future of Exchange is as a foundation component of this integrated unified communication services infrastructure we are building," says Dave Thompson, corporate vice president of the Exchange group at Microsoft.

Microsoft is making these moves with some competitive prodding from longtime rival IBM/Lotus, which is crafting its own platform that integrates messaging, collaboration and real-time communications, such as instant messaging.

Microsoft is likely to have a challenge converting users to Exchange 2007 when it is released, given that nearly a quarter of its user base migrated off Exchange 5.5 in the past year. Those users likely won't be upgrading in the near future even if they have Software Assurance maintenance contracts that provide access to the Exchange 2007 upgrade.

However, Microsoft last fall said it still had 16% of its installed base on Exchange 5.5, a group that would be prime candidates for an upgrade but also are being tempted by IBM/Lotus, open source e-mail vendors and others.