It's interesting that you mentioned mailchimp. We've had the same issues with 
mailchimp. We have contacted them before about people abusing their services 
and they don't seem very interested in doing anything about it, hence I 
wouldn't consider blocking their IPs a bad thing but that's another discussion.

The only way that I know to add spam scores is by creating SA rules. I don't 
think Amavis can add scores on its own unless someone knows another approach to 
this. Regardless, if you don't want to use SQL then you are going to have to 
parse the log files for sender sending to your honeypot receivers and add those 
to a SA rule in order to add the +5 spam score. Again, the entire problem with 
this approach is you are using valuable resources processing e-mail (i.e. 
letting it get to Amavis) instead of stopping it at the front door with Postfix.



-----Original Message-----
From: Patrick Proniewski [mailto:patrick.proniew...@univ-lyon2.fr] 
Sent: Tuesday, March 14, 2017 7:29 AM
To: amavis-users@amavis.org
Cc: Dino Edwards <dino.edwa...@mydirectmail.net>
Subject: Re: spamtrap and dynamic blacklisting

Hi Dino,

I'm not so sure. Of course sender is potentially forged, but I have a slightly 
different goal than just spam filtering here.

I have many users (about 40k students+staff+other), and get around 35K messages 
a day into Amavisd (way more try to come in and are blocked by 
greylist/blacklist/SPF/...). What we often see is mass mailing from "grey" 
senders, or from mailchimp or other mass mailing solutions : not totally spam. 
Some of these senders use address lists that are legitimate, but often it's 
only illegitimate address lists (web site harvesting, blackmarket/spam 
resell…). I want to block all these illegitimate mass mailings, while letting 
legitimate mass mailings in.
ie. I can't block Mailchimp servers, I want to block a specific Mailchimp user, 
hence rely on sender address.

Phishing also uses harvested email addresses, and to my experience, phishers 
don't change sender address, they use the same for thousands recipients, so I 
could easily block phishing campaign with only the sender address.

And I don't want to block immediately the sender, I want it to get a bonus to 
it's spam score, say +5. Complete blacklist using Postfix could be quite 
straightforward to setup as I already got a shell script able to push different 
files (client_access, client_access_cidr, header_checks, recipient_access, 
recipient_bcc, sender_access) to all MX servers.

(I'm subscribed to digest, please Cc me)


Patrick

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