Greylisting .. nice ..

John Rudd jrudd at
Sat Nov 4 05:12:54 GMT 2006

Res wrote:
> On Fri, 3 Nov 2006, Rob Poe wrote:
>> My thoughts so far are this:  Why didn't I do this sooner.
> Its going to be pointless soon, problem is, as more and more people do 
> this, it wont be long before the common garden variety spammers smtp engine
> will also retry on 4xx errors, id give it a year tops (if some of them 
> are not already doing it)

Defeating Greylisting is almost trivial.  I even outlined how to do it 
on the SA list at one point (because I thought someone was trying to use 
it on me, even though I don't use greylisting).  I'd be surprised if 
takes a full year to see it in the field.  I'd be surprised if some 
botnets aren't already adapting to it.

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