This update contains a number of customer-reported and internally found issues since the release of SP1. See 'KB 2582113: Description of Update Rollup 5 for Exchange Server 2010 Service Pack 1' for more details.
We want to let you know this rollup contains the Exchange 2010 SP1 version of the change described in this KB article:
2543879 PDF attachment from a Mac Mail client is not displayed when you use Outlook 2010 to open the email message in an Exchange Server 2007 SP3 environment
We would also like to specifically call out the following fixes which are included in this release:
2555850 Unable to delete a folder whose name has a particular character code
2490134 OWA's zip-download does not work for some messages due to invalid chars in the subject
Some of the above KnowledgeBase articles are not replicated/live at the time of writing this post. Please check back later in the day if you can't reach them.
Availability of this update on Microsoft Update is planned for late September. Update Rollup 6 for Exchange Server 2010 Service Pack 1 is currently scheduled to release in October 2011.
Note for Exchange 2010 Customers using the Arabic and Hebrew language version: We introduced two new languages with the release of Service Pack 1, Arabic and Hebrew. At present we are working through the process of modifying our installers to incorporate these two languages. Customers running either of the two language versions affected are advised to download and install the English language version of the rollup which contains all of the same fixes.
Note for Forefront users: For those of you running Forefront Security 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.