If you missed it, the problem was caused by a date verification bug in Microsoft’s Exchange server antivirus engine as it moved to the year 2022. As a solution, according to Microsoft, IT administrators can now download an automated solution to fix the problem.
To get the fix, IT administrators can follow these steps. First, change the PowerShell script execution policy by running Set-ExecutionPolicy -ExecutionPolicy RemoteSigned. Next can be the script downloaded with a simple click. Finally, the script can be run on any Exchange Mailbox server that is downloading antimalware updates.
There is also a manual solution should an admin prefer. According to Microsoft, the solution to this problem is currently automated as it can take some time to make changes, download updated files, and clear transport queues. However, the company makes it clear that any manual or automated solution must be performed on every on-premises Exchange 2016 and Exchange 2019 server. The script can even be run on multiple servers at the same time.
In all cases, Microsoft’s emergency script may take some time to run. It may also take some time for the script to clean up any missed messages in the transport queue. The response to the script / fix has been mixed, some saying it works and others saying it doesn’t. Others report that running the script multiple times could help fix the problem.