Exchange Server Quarterly Updates – March 2021

I like to post the Exchange Server CU Updates when they are released by the Exchange Team. It is important to keep up to date with the Exchange Updates especially after the Zero Day threat that came out the early part of March. Thank you for your continued reading and patronage!


Today we are announcing the availability of quarterly servicing cumulative updates (CUs) for Exchange Server 2016 and Exchange Server 2019. These CUs include fixes for customer reported issues as well as all previously released security updates. Although we mentioned in a previous announcement that this release would be the final cumulative update for Exchange 2016, we do expect to release one more CU for Exchange 2016 next quarter which will includes all fixes made for customer reported and accepted issues received before the end of mainstream support.

A full list of fixes is contained in the KB article for each CU, but we wanted to highlight that these latest CUs contain the fixes that were previously released as Exchange Server Security Updates on March 2, 2021. This means you don’t have to install the March 2021 Security Updates after installing the March 2021 CUs.

The KB articles that describe the fixes in each release and product downloads are 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. These updates contain schema and directory changes and so require you prepare Active Directory (AD) and all domains. You can find more information on that process here.

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 these resolution steps to adjust the settings.

Additionally, a reminder that if you plan to install any Cumulative Update using the unattended option with either PowerShell or Command Prompt, make sure you specify either the full path to the setup.exe file or use a “.” in front of the command if you are running it directly from directory containing the update. If you do not the Exchange Server Setup program may indicate that it completed successfully when it did not. Read more here.

Reminder: Customers in hybrid deployments where Exchange is deployed on-premises and in the cloud, and those using Exchange Online Archiving with their on-premises Exchange deployment are required to deploy the currently supported CU for the product version in use.

For the latest information on the Exchange Server and product announcements please see What’s New in Exchange Server and Exchange Server Release Notes.

Note: Documentation may not be fully available at the time this post is published.


Released: March 2021 Quarterly Exchange Updates – Microsoft Tech Community

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