Microsoft has expanded the number of beta participants for Exchange 12 with a new test build of the software.

Microsoft released Beta 1 of the next version of its e-mail server software in December, but only 1,400 users had access to that release, said Megan Kidd, an Exchange senior product marketing manager for Microsoft. The Community Technology Preview (CTP) of Exchange 12 will reach about 200,000 more beta testers, she said.

The CTP is available online to Microsoft Developer Network (MSDN) subscribers and is currently in route via postal mail to TechNet subscribers, Kidd said. TechNet provides early access to software releases for Microsoft technical enthusiasts.

Microsoft expects to make Exchange Server 12 generally available in late 2006 or early 2007, she added.

Microsoft has added no substantial new features other than a few minor bug fixes to the CTP, Kidd said. However, the company said it has received positive feedback on the continuous replication feature that is already included in the software as part of Beta 1.

That feature, which is included for evaluation, has two flavours - one for small-and-medium-sized business customers and one for enterprises that may have multiple servers running Exchange, said Ray Mohrman, an Exchange technical product planner for Microsoft.

Exchange 12 will continuously replicate data to local machines for companies that have only one e-mail server, he said. For larger customers with clusters of servers running Exchange, the software can continuously replicate data to a back-up machine so if one of the main Exchange servers goes down, there will be little to no downtime or loss of data, Mohrman said.

The CTP also is available in 32-bit and 64-bit versions, like Beta 1. However, Microsoft will release Exchange 12 for 64-bit servers only, a decision that has met with some concern by customers because it could require them to purchase new hardware.