[Sophos Notification] Email Appliance messages are getting a Pre-Filter deferred error and never delivers

Summary: 

Error does not seem to appear for every message but it can cause message build up in the mail queue since it is never processed

Version:

Seen in version 4.2.1.1 and 4.2.2

Who is affected:

If you have CCL rules then you are likely affected by this issue

Workaround:

Disable your CCL rules in Configuration -> Policy -> Data Control. Either until this issue is resolved or until the queue clears out. You can reprocess the message from the mail queue search section.

Our Development team is investigating.

Please follow our KB article: Advisory: Sophos Email Appliance messages getting Pre-Filter deferred error and never deliver. for updates on the issue.

Thanks,
Karlos