Re: IETF SMTP Working Group Proposal at smtpng.org

[Barry Shein <bzs () world std com>]

If you want slower e-mail delivery why not just put sleeps into the
receiving MTA?

I've often wondered if keeping a little db of who has connected lately
and using the number of connects from a particular address as a factor
in a delay calculation wouldn't help against certain common spam
attacks.

An exception list of known big sites you get a lot of mail from would
be a desireable, additional feature, maybe optionally as a fudge
factor since large sites can also be spam sources. etc etc etc.

But so would refinements like increase the slope if (some criteria
like serious mismatch between from and relay or can't DNS relay or IP
addr is in known suspect range.)


On August 22, 2002 at 22:45 brad.knowles () skynet be (Brad Knowles) wrote:
> At 7:20 PM -0500 2002/08/21, J.A. Terranson wrote:
>
> >  Presenting a computationally difficult problem to a connecting MTA
> >  moves the requirement for the CPU power to the sender while keeping
> >  the recipient site unfettered.  Let's face it, the spam problem is
> >  merely one of cost shifting from sender to reciever, and this
> >  proposal shifts the load back.  Any site that wishes to maintain
> >  the current system of email subsidies to the sender domain need
> >  only provide a computationally simple token.
>
>      Now this is more plausible.  You'd still need something akin to a 
> PKI to distribute the computationally simple tokens, and you'd need a 
> way to easily revoke them.  But if this was implemented by default in 
> the standard MTAs, you would go from hundreds or thousands of message 
> deliveries per minute to five or more minutes per un-authenticated 
> message delivery.
>
>      This is something that might be worth discussing in the 
> appropriate forums, such as the SMTP-related working groups of the 
> IETF.
>
> -- 
> Brad Knowles, <brad.knowles () skynet be>
>
> "They that can give up essential liberty to obtain a little temporary
> safety deserve neither liberty nor safety."
>      -Benjamin Franklin, Historical Review of Pennsylvania.
>
> GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E W+++(--) N+ !w---
> O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
> tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)

-- 
        -Barry Shein

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