On Wed, 2009-09-23 at 15:54 -0700, Ted Mittelstaedt wrote:
> RW wrote:
> > Incidently the point about backscatter is wrong. The traditional
> > approach of classifying, and then discarding or filing to a spam folder,
> > produces zero backscatter from spam. Backscatter is actually caused by
> > rejecting at the SMTP level - when it's done on the wrong
> > SMTP transaction.
>
> Say what?!?!?
>
> http://en.wikipedia.org/wiki/Backscatter_(e-mail)
>
> "...The recipient mail servers then use the (potentially forged)
> sender's address to attempt a good-faith effort to report the problem to
> the apparent sender...."
>
> There's 2 separate and independent SMTP transactions here.
>
> The first is the spammer to the recipient mailserver.
>
> The second is the recipient mailserver to the apparent sender.
>
> "rejecting at the SMTP level" makes no sense at all in your context.
It does. What you just described, however, is *bouncing*, a.k.a.
"rejecting after accepting". That's not rejecting -- by the MX, mind
you.
--
char *t="\10pse\0r\0dtu...@ghno\x4e\xc8\x79\xf4\xab\x51\x8a\x10\xf4\xf4\xc4";
main(){ char h,m=h=*t++,*x=t+2*h,c,i,l=*x,s=0; for (i=0;i<l;i++){ i%8? c<<=1:
(c=*++x); c&128 && (s+=h); if (!(h>>=1)||!t[s+h]){ putchar(t[s]);h=m;s=0; }}}
