On August 13th 2012, the Exchange CXP team released Update Rollup 4 for Exchange Server 2010 SP2 to the Download Center. This update contains fixes for a number of customer reported and internally found issues. See KB 2706690 Description of Update Rollup...

Microsoft has released Update Rollup 4 (KB982639) for Exchange Server 2010. This update rollup is highly recommended for all Exchange Server 2010 customers. For a list of changes that are included in this update rollup, see KB982639 . This is a cumulative...

http://msexchangeteam.com/archive/2008/09/11/449787.aspx For a brief period of time on 9/9 (Tuesday), a pre-release version of Update Rollup 4 for Exchange Server 2007 Service Pack 1 (KB952580) was inadvertently made available to Microsoft Update, the...