Microsoft released an emergency fix for the year 2022 bug-breaking email delivery on on-premise Exchange servers. Exchange admins worldwide discovered that their servers were no longer delivering email.
After investigating, they found that mail was getting stuck in the queue, and the Windows event log showed one of the following errors. These errors are caused by Microsoft Exchange checking the version of the FIP-FS antivirus scanning engine and attempting to store the data in a signed int32 variable.This variable can store only a maximum value of 2,201,010,001, which is less than the new date value of 2,201,010,001 for January 1st, 2022, at midnight.
When executed, the hand will stop the Filtering Management and Exchange Transport services, delete older AV engine files, download the new AV engine, and start the services again. Microsoft also explains that the latest AV scanning engine will be version number 2112330001, which references a date that does not exist and that admins should not be concerned about.