Exchange 2016 Antimalwarescanning Antimalware scanning FIPFS issues

[ANAND_SUNKA]

Hi MSFT Exchange Team,

Most of the on-premise Exchange 2016, 2019 customers facing suddenly mail flow issues as they cannot send/receive emails.

Fix is Set-MalwareFilteringServer -BypassFiltering $True -identity <Server Name>.

But disabling or bypassing the Filtering rule is not a good idea or not recommended.

Please can you shed some light and share the permanent fix for the same.

Regards

Anand S

[#2]

Exactly the same problem !!!

I spent a few hours before finding the solution and identifying the cause of the email blocking.
After deactivating the spam filter, my emails came back.
The most worrying thing is knowing that it is the first day of the year and that there is already a major bug ...

[#3]

I started seeing the same problem across 3 separate Exchange environments starting 12/31 between 12:30pm-4pm Pacific time. Exchange 2016 and 2019. Running different types of EDR/AV. Followed the below article until I came to the same conclusion of disabling malware filtering. I agree this is a less than ideal workaround.

https://techcommunity.microsoft.com/t5/exchange/last-error-message-deferred-by-categorizer-agent/m-p...

[#4]

I am facing the same issue. Can someone update if there is any other solution

[#5 · Accepted solution]

The official fix has been released here: https://techcommunity.microsoft.com/t5/exchange-team-blog/email-stuck-in-exchange-on-premises-transp...

[#6]

Hi secabstraction,
Thanks for the fix as I got already from the msft team on the same day and followed this article for all my on-premise exchange customers.

Regards
Anand Sunka