>
> Josip Rodin wrote:
> > On Wed, Nov 29, 2006 at 11:42:10AM -0500, Dean Brooks wrote:
> >
> >> Keep in mind that there *are* sites out there that:
> >>
> >> - Dont ever retry at all
> >> - Retry only once after one hour
> >> - Retry once only every 24 hours
> >> - Treat temporary errors as failures
> >> - etc.
> >>
> >
> > I recently encountered one ISP which retries in fifteen
> minute intervals,
> > but only three times, before it gives up. Wackos.
> >
> >
>
> And therein lies the rub. I think the solution is to apply
> greylisting
> selectively rather that to everyone. Suppose that you only applied
> greylisting to hosts that:
>
> Have bad RDNS
> In home/dynamic IP ranges
> Fail and header test
> Has any slightly weird HELO
> Mail From:<>
> Listed in Blacklists like Spamcop that are not good enough to block on
>
> What that you will probably block almost as much spam without
> the delays.
In its simplest form this is a fantastic idea, thank you. Of course you
would want to greylist given the fact that you have a reason to do so. I am
going to immediately try to figure out how to set up the ACL to try this
out.