The Exchange team is announcing today the availability of our most recent quarterly servicing update to Exchange Server 2013. Cumulative Update 5 for Exchange Server 2013 and updated UM Language Packs are now available on the Microsoft Download Center. Cumulative Update 5 represents the continuation of our Exchange Server 2013 servicing and builds upon Exchange Server 2013 Service Pack 1. The release includes fixes for customer reported issues, minor product enhancements and previously released security bulletins. A complete list of customer reported issues resolved in Exchange Server 2013 Cumulative Update 5 can be found in Knowledge Base Article KB2936880. Customers running any previous release of Exchange Server 2013 can move directly to Cumulative Update 5 today. Customers deploying Exchange Server 2013 for the first time may skip previous releases and start their deployment with Cumulative Update 5 as well.
Note: Some article links may not be available at the time of this post's publication. Updated Exchange 2013 documentation, including Release Notes, will be available on TechNet soon.
We would like to call your attention to a couple of items in particular about the Cumulative Update 5 release:
Based upon customer feedback, we have introduced improvements to OAB management for distributed environments. You can read more about this in a post by Ross Smith IV on the Exchange Team blog. Customers who have deployed Multiple OAB Generation Mailboxes are advised to read this post to help avoid unnecessary OAB downloads.
Cumulative Update 5 includes a Managed Availability probe configuration that is frequently restarting the Microsoft Exchange Shared Cache Service in some environments. The service is being added to provide future performance improvements and is not used in Cumulative Update 5. More information is available in KB2971467.
Cumulative Update 5 includes Exchange related updates to Active Directory schema and configuration. For information on extending schema and configuring the active directory please review the appropriate TechNet documentation. Also, to prevent installation issues you should ensure that the Windows PowerShell Script Execution Policy is set to “Unrestricted” on the server being upgraded or installed. To verify the policy settings, run the Get-ExecutionPolicy cmdlet from PowerShell on the machine being upgraded. If the policies are NOT set to Unrestricted you should use the resolution steps in KB981474to adjust the settings.
Reminder: Customers in hybrid deployments where Exchange is deployed on-premises and in the cloud, or who are using Exchange Online Archiving (EOA) with their on-premises Exchange deployment are required to deploy the most current (e.g., CU5) or the prior (e.g., CU4) Cumulative Update release.