Greylisting .. nice ..

[John Rudd]

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.