Earlier today the Exchange CXP team released Update Rollup 7 for Exchange Server 2007 SP3 to the Download Center.
This update contains a number of customer-reported and internally found issues since the release of SP3 RU6. See KB2655203: Description of Update Rollup 7 for Exchange Server 2007 Service Pack 3 for more details.
Note: Some of the following KB articles may not be available at the time of publishing this post.
Support lifecycle statement: This is the final release under standard support for Exchange 2007, as the Exchange 2007 Mainstream Support has now ended. Extended Support for Exchange 2007 SP3 will end on 4/11/2017. Please see the Microsoft Support Lifecycle page for more information about Microsoft Support Lifecycle for Exchange 2007.
Note for Forefront Protection for Exchange users For those of you running Forefront Protection for Exchange, be sure you perform these important steps from the command line in the Forefront directory before and after this rollup’s installation process. Without these steps, Exchange services for Information Store and Transport will not start after you apply this update. Before installing the update, disable ForeFront by using this command: fscutility /disable. After installing the update, re-enable ForeFront by running fscutility /enable.