Hi,
From: "Paul Schinder" <[EMAIL PROTECTED]>
> At 3:06 PM -0500 3/31/00, Dave Sill wrote:
> >Do the spammers:
> >
> > 1) throw up their hands and admit defeat, or
> > 2) start using valid (but wrong) domains in their envelope return
> > paths, thereby defeating your rejection and escalating the arms
> > race?
> >
> >Note that many are already doing (2), of course.
>
> I've had several emails using my @pobox.com address as the MAIL FROM
> bounced because spammers use phony @pobox.com addresses. I've never
> seen a single spam that originated on pobox's servers. Most of the
> spam I see comes from China or relay raped machines outside the US.
> And, of course, I've seen numerous pieces of spam with phony
> @yahoo.com, @hotmail.com, @aol.com, etc.
>
Maybe one way to deal with this is:
1. verify that the domain of MAIL FROM is correct
2. verify that the address of the server sending the mail
resolves to that domain...
This is probably not the best answer, but if you apply that to some key
domains, then you should be able to cut down on a fairly good volume of spam
with fake addresses. Also it should be fairly easy to implement a scheme
like this in qmail (although it also means more DNS lookups for a good
number of incoming mail messages).
Patrick.
