Microsoft has released the first beta for the next version of Exchange and said the software will be generally available in late 2006 or early 2007.

The beta of Exchange, code-named Exchange 12, will be private and available only to a select number of partners and customers.

Microsoft plans a beta 2 in mid-2006, but has yet to decide if that release will be private or public. The beta 2 release also is expected to be feature-complete or near-feature-complete.

Microsoft said it expects the final release of Exchange 12 to come no later than early 2007.

Microsoft is focusing beta 1 on three sets of features: administration, access to the inbox from various sources, and compliance.

Exchange 12 is being built around the concept of server roles, according to Jeff Ressler, directory of product planning on the Exchange team at Microsoft. Administrators will be able to deploy any combination of five roles when they deploy the server, according to Ressler.

The roles include unified messaging; edge transport, which is a gateway for the edge of the network; hub transport, which is the message transport agent and the primary way to secure internal mail traffic; a mailbox role for storage; and the client access services role, which is a middle tier to support mobile devices and Outlook Web Access.

"With this more modular approach around roles, administrators can control the working set around Exchange," Ressler says.

Microsoft has rewritten Exchange System Manager, which will use the roles for operational management. Microsoft also has added a scriptable command-line shell based on its Monad technology. Users could write scripts in Exchange 2003, but they had to use Visual Basic scripting that was very complex, according to Ressler.

For the inbox, Microsoft has added support for a unified mailbox, including voicemail and fax. Exchange 12 will include speech recognition software so that users can call into the server and retrieve or send mail. Outlook Web Access also is redesigned for Exchange 12 and will feature improvements in group calendaring and scheduling.

On the security front, Microsoft is adding a new anti-virus API that will allow for deeper content scanning, including attachment filtering. Ressler would not say if Microsoft plans to include the company's own anti-virus technology directly in the server. The server also will expand on the anti-spam features of Exchange 2003 SP2, including deeper filtering options and better updating features.