[Mimedefang] Blocking Dictionary Attacks

Matt Garretson mattg at assembly.state.ny.us
Thu Jun 11 10:23:33 EDT 2009

Petra Humann wrote:
> Do you know the sendmail badrcpt_shutdown patch?
> http://www.jmaimon.com/sendmail/
> After an defined number of bad recipients the SMTP session terminates:
> "Possible SMTP RCPT flood, shutting down connection."

I hadn't heard about that patch.  But even without the patch,
you can do basically the same things.  I have this in my 



# Reject if lots of bad addresses:
R $*            $: $&{nbadrcpts}
R $+            $: $(arith l $@ $1 $@ 8 $)
R FALSE         $# error $@ 5.1.2 $: "553 Too many bad recipients"

I guess this is getting a bit off-topic, though.


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