As digital calendars around the world changed to 01.01.2022, Microsoft customers found their Exchange servers stopped processing emails. According to Microsoft, the issue relates to a date check failure in the change of the year from 2021 to 2022. Microsoft has confirmed that it is working on a fix for the FIP-FS engine (antivirus engine) on Microsoft Exchange 2016 and 2019 Servers that could result in emails being struck in transit. As a workaround, it’s being suggested to disable or bypass malware scanning on Exchange servers, but only if customers have an existing malware scanner other than Exchange’s own solution.
The Exchange Team has also created a script to correct this issue and essentially clears all previous updates and load a new update for FIP-FS service. The good thing about this update is you can use the automated script provided by Microsoft if you choose to but they have also documented in the article exactly what is happening. Also, this script must be run on ALL the Exchange servers in your environment.
After running the script you must check to see if you have the new update version as instructed: “Get-EngineUpdateInformation and verify that the UpdateVersion information is 2112330001.” Then you can run the enable-antimalwarescanning.ps1 to undo the previous workaround. Remember to also restart the Microsoft Exchange Transport Service via Restart-Service MSExchangeTransport or however you choose. At this point you can use Get-Queue to see if everything is flushing and you are back to normal operations.