RE: [exim] A type of spam

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Author: David Brodbeck
Date:  
To: exim-users
Subject: RE: [exim] A type of spam
> -----Original Message-----
> From: Gururajan Ramachandran [mailto:gururajan20815@yahoo.com]


> Can I check for the type of spam where an email is
> sent
> to a bunch of recipients with many non-existent
> addresses? I would like to use the threshold of say
> three non-existent email addresses or something like
> that and reject the email on that basis. Is something
> like this in the online manual. I looked but was
> probably looking on the wrong places.


In Exim 4, I use this in the RCPT ACL:

  # "Rumplestiltskin attack" rejection -- after the fifth bad recipient,
  # the connection is dropped.
  drop condition = ${if >{$rcpt_fail_count}{5}{1}{0}}
     message = Too many bad recipients.


Another options is to throw in "delay" modifiers after a certain number of
bad recipients, to slow them down. I did that for a while, but ultimately
decided I'd rather just drop the connection.