The Exchange Team has just released the latest Rollup Update (ver. 4) for Exchange 2010 SP2.
Update Rollup 4 for Exchange Server 2010 Service Pack 2 resolves issues that were found in Exchange Server 2010 Service Pack 2 since the software was released. This update rollup is highly recommended for all Exchange Server 2010 Service Pack 2 customers.
The changes/fixes of the RU4 is documented in KB2706690.
This updates raises Exchange 2010 build number to 14.2.318.2.
Rollup Updates are cumulative, which means that they contain all the fixes released in earlier Rollup Updates. So there is no need to install a previous Rollup Update, when doing a fresh install of Exchange 2010 SP2, always just install the latest Rollup Update.
Edited 15 August – about the usual disabling of Forefront Protection for Exchange (FPE) when running Rollup Updates:
This has been fixes in this update, so there is no need disabling FPE services before installing.
2743871 Stop Forefront services in RU setup so no manual steps are required.
Reference: Exchange Team Blog post.
Download the Exchange 2010 SP2 RU4 at Microsoft Download.