SMTP Blocking vs Trusted Senders precedence
Question asked by Camilo Torres - January 4, 2017 at 5:56 AM
Hi, is there any information that will explain what is the precedence in which the SMTP Blocking and the Trusted Senders checks are performed?
I want to block the ".us" domains on SMTP Blocking, **EXCEPT** for one ".us" domain, but i'm not sure if the SMTP Block will occur first even if the exception is created in the Trusted Sender.

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I would also like to know the answer to this. There are older posts about older versions that explain this to be the case, but in my own testing it appears the SMTP blocking of a domain happens first before the trusted senders list is checked.
We are on the newest version of SM. *.US domains have been particularly bad of late in regards to spam - it would be nice to be able to lock that down with exceptions.
This is the response i got from Smarter Mail support:
"If a server address has both a blacklist entry, and an SMTP Auth Bypass entry configured for it - the blacklist entry will take precedence. This means that even if the server is whitelisted, the blacklist will take precedent. This is security best practices, and is the industry recommendation."

The way i did it was by using Custom Anti-spam Rules: i created a rule for all ".us" to have a 50 points weight and then a rule for -50 for all ".us" that i wanted to have an exception and finally, i then changed the Filtering action for High Spam Probability so a 50 or more would be deleted.

This asssumes that no other rules will ever make the points of spam probability to get to 50 and if it reaches that point it is safe to delete it, which is not much different than rejecting the SMTP connection.

Good luck.

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