The new service pack was released on Sunday, but was announced yesterday, and can be downloaded here. Microsoft took time to deliver this service pack because it entailed making a lot of coding changes to Exchange 2007, the company explained late last year. Microsoft promised back then that it would deliver SP3 in the second half of this year, so this release came early.
The arrival of the service pack means that organizations don't have to move off Exchange Server 2007 if they have migrated to Windows Server 2008 R2 already. Exchange 2010 is currently available, having been released as a final product in November, but some organizations may not be ready to make that move. For example, Exchange 2010 uses a different method of archiving and storing e-mails from its predecessors that may require infrastructure changes.
However, the release notes for SP3 suggest that IT pros won't have a simple upgrade process. SP3 will cause Active Directory schema changes, so Microsoft's release notes suggest preparing Active Directory and domains prior to installing this service pack.
SP3 is cumulative, meaning that it contains update rollups through the fourth release. Consequently, it allows users to upgrade from earlier service packs (such as SP1). However, Microsoft says that users must first "uninstall all Interim Updates before you install Exchange 2007 SP3."
Removing SP3 appears to be less simple than installing it. The only way to uninstall SP3 is to remove Exchange Server 2007 entirely and reinstall an earlier version, according to Microsoft's release notes.
SP3 will work on Windows Server 2008, but not if the OS was previously upgraded. Microsoft offers just one approach: "To deploy Exchange 2007 SP3 on an Windows Server 2008-based computer, you must first install Windows Server 2008 on a computer that does not have Exchange installed, and then install Exchange 2007 SP3."
Exchange Server 2007 SP3 supports both 32-bit and 64-bit machines. However, a Microsoft blog notes that "only the 64 bit is supported in Production environment[s]."
A few new features are available with SP3. Highlights include the ability to install Exchange Management Tools on Windows 7 computers, as well as an improved search and password reset capabilities.
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