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 wel...
Updated Mar 18, 2021
Version 4.0
Blog Post
I want to comment since no from Microsoft has.
They state "This is the most effective way to help quickly protect and mitigate your Exchange Servers prior to patching. We recommend this script over the previous ExchangeMitigations.ps1 script. The Exchange On-premises Mitigation Tool automatically downloads any dependencies and runs the Microsoft Safety Scanner. This a better approach for Exchange deployments with Internet access and for those who want an attempt at automated remediation. We have not observed any impact to Exchange Server functionality via these mitigation methods."
I ran them with permission from management near the end of a business day and running this script absolutely impacted Exchange! I monitored both of our servers and CPU utilization and on our 16 server that needed updates the CPU went to 100% for a good 15 minutes and no one was able to use email until the EOMT script finished. It is my recommendation that if you need to run these tools do so knowing that you are likely to cause an interruption to email services.
https://github.com/microsoft/CSS-Exchange/tree/main/Security