nDLP and MEG: Setting an NDR for emails that bypassed inspection
We've had an issue recently due to an issue with emails not going in to the nDLP Prevent appliance and the emails were sent out to the world without going through any inspection.
We want to prevent this from happening again and create a blackhole/NDR condition for these emails when Prevent for once reason or another does not get the emails to inspect.
In the headers of the emails that get inspected, nDLP prevent adds in a line that says X-RCIS-ACTION: <whatever action the MEG should take based upon inspect results)
I want to use this line because it's the most definitive way to show that inspect has occurred, but there does not appear to be a NOT statement that can be uses within the MEG that basically says "If X-RCIS-ACTION: is NOT in header, NDR message and send warning to sender"
I think the only way I can do it is to say "Allow message that has X-RCIS-ACTION:", but I have a strong suspicion that this will interfere with the nDLP response codes that are already in use by the Post DLP Inspection and Internet delivery policy.
Has anyone had any experience with this? Thanks in advance! (P.S. to the Mods; if this post would be better served in the MEG community, please feel free to move it.)