Note: We have learned that customers using Exchange Server 2013 and Exchange Server 2007 co-existence can experience an issue causing Exchange Server 2013 CU6 databases to failover. Please refer to KB2997209 for the specific scenario impacted.
The Exchange team is announcing today the availability of our most recent quarterly servicing update to Exchange Server 2013. Exchange Server 2013 Cumulative Update 6 and updated UM Language Packs are now available on the Microsoft Download Center. CU6 represents the continuation of our Exchange 2013 servicing and builds upon Exchange 2013 CU5. 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 2013 CU6 can be found in KB 2961810. Customers running any previous release of Exchange 2013 can move directly to CU6 today. Customers deploying Exchange 2013 for the first time may skip previous releases and start their deployment with CU6 as well.
We would like to call your attention to a couple of items in particular about the CU6 release:
CU6 includes a fix for the HCW issue discussed in KB 2988229. A reminder for those customers who installed the Interim Update which resolved this issue: it's NOT necessary to uninstall the Interim Update prior to installing CU6.
CU6 includes Exchange-related updates to Active Directory schema and configuration. For information on extending schema and configuring Active Directory, please review Prepare Active Directory and domains in Exchange 2013 documentation.
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., CU6) or the prior (e.g., CU5) Cumulative Update release.
Note: Documentation may not be fully available at the time this post was published.