Released to business customers as part of Microsoft's roll-out wave of new products. It includes new clustering options, x64 support for greater scalability, voice mail integration, better search&support for Web services, better filtering options, and a new Outlook Web Access interface. Exchange 2007 also dropped support for Exchange 5.5 migrations, routing groups, admin groups, Outlook Mobile Access, X.400, and some API interfaces, amongst other features.
Exchange Server 2007 (v8, code name E12, or with SP1 v8.1) runs only on x64 versions of Windows Server. This requirement applies to supported production environments only; a 32-bit trial version is available for download and testing. Hence, companies currently running Exchange Server on 32-bit hardware will be required to replace or migrate hardware if they wish to upgrade to the new version. Companies that are currently running Exchange Server on 64-bit capable hardware are still required to migrate from their existing Exchange 2000/2003 servers to a new 2007 server since in-place upgrades are not supported in 2007.
The first beta of Exchange Server 2007 (then named "Exchange 12" or E12) was released in December 2005 to a very limited number of beta testers. A wider beta was made available via TechNet Plus and MSDN subscriptions in March 2006 according to the Microsoft Exchange team blog. On April 25, 2006, Microsoft announced that the next version of Exchange Server would be called "Exchange Server 2007".