[exim] Re: heads-up: some spam bots started RCPT flooding

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Autor: Markus Reschke
Datum:  
To: Jeremy Harris via Exim-users
Betreff: [exim] Re: heads-up: some spam bots started RCPT flooding
On Sun, 14 May 2023, Jeremy Harris via Exim-users wrote:

Hi!

> On 14/05/2023 18:56, Markus Reschke via Exim-users wrote:
>> They take a list of common user names, add your domain name, and then loop
>> through 100 RCPT TOs per mail.


> An escalating delay per RCPT *reject* isn't hard.


I was able to keep each spambot's connection about 6 hours open. >:) The
drawback is that you run the same amount of exim processes all that time.
So I moved to a simple ACL rule to drop the connection when the first x
recipients are rejected:

drop  message = Too many bad recipients
       condition = ${if and 
{{>{$rcpt_count}{5}}{=={$recipients_count}{0}}}{yes}{no}}


ciao
  Markus
-- 
/ Markus Reschke              \
\ madires@??? /



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