Today we are announcing the availability of quarterly servicing cumulative updates for Exchange Server 2016 and 2019. These updates include fixes for customer reported issues as well as all previously released security updates.
Changes to OWA’s Blocked File Extensions
This quarterly update adds additional file types to the default OWA Mailbox Policy BlockedFileTypes list. The new extensions added to this list are listed in KB4559446. This change was made to increase security by preventing users from being able to download these attachment types.
Addition of Pipelining Support to Restore-RecoverableItems
This update also addresses a customer reported issue whereupon the Restore-RecoverableItems didn’t support pipelining which made its use more difficult. This update adds pipelining support to this cmdlet. You can find more details in KB4547707.
The KB articles that describe the fixes in each release and product downloads are available as follows:
Microsoft recommends all customers test the deployment of any update in their lab environment to determine the proper installation process for your production environment. For information on extending the schema and configuring Active Directory, please review the appropriate 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 here to 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 currently supported cumulative update for the product version in use, e.g., 2013 Cumulative Update 23; 2016 Cumulative Update 17 or 16; 2019 Cumulative Update 6 or 5.