Autor: Alun Data: A: Fred Viles CC: exim-users Assumpte: Re: [Exim] Greylisting + multiple MX hosts -> multiple attempts
Fred Viles (fv+exim@???) decreed: >
> I'm not so sure it is a valid assumption, however. I think normal
> MTA queue management and retry behavior would indeed be very
> burdensome for the spammers, but ISTM dedicated spamware wouldn't
> need to do that. A technique like simply running through their
> address list twice in two hour chunks would do the job.
I suspect that this will come. That's why I'm thinking about variable
delays here. If they want to get a pile of addresses through the greylist
at any sane sort of speed, they've got to have a pile of attempts in the
"grey" state. If we can find any way of tying those attempts together (e.g.
by source IP address, we can penalise them by upping the delay time).
I think it should make things harder for them when they go for that
approach...
Cheers,
Alun.
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