Re: [Asrg] Re: bounces, and anit-spam principles

On Jan 22, 2007, at 11:25 PM, David Nicol wrote:

> On 1/22/07, Dan Oetting <dan_oetting(_at_)qwest(_dot_)net> wrote:
> > That works if you don't mind taking the long route. I was thinking of
> > a more direct path of sending a specific response code in the SMTP
> > transaction. A really smart smarthost might be able to then fix the
> > problem before the site gets blacklisted.
> >
> > -- Dan Oetting
> I for one caught that drift.  It wouldn't need to be its own ESMTP  
> keyword,
> just some specific text following the 550 rejected on policy  
> grounds.  Perhaps
> the word "spam."
>
> So, a conformant sending domain, on seeing a /^550 .+spam/i  
> response, would
> do what exactly? Log the fact?  Page a sysadmin?
Just like most blacklists wouldn't list a site for a single email  
hitting a spamtrap, the host would not be expected to take action  
against a user for sending the single email unless there were  
extenuating circumstances. If the host is on probation or a gray list  
for currently spamming it may be necessary to throttle the user to  
prevent escalation to a blacklist.
You don't want to reveal the spamtrap address to the user. If the  
users account has been taken over by a spammer it could wash the  
address from its lists and then you loose that method of identifying  
the spamers next identity. These traps should not be used for  
blacklisting because if they are identified by the spammers they  
could be abused to generate false listings.
The spamtraps should only be revealed between cooperating ISPs. And  
each trap should only reveal itself to a fraction of the connecting  
hosts to keep from revealing all the traps to a rogue ISP that joins  
the group. The response code given to reveal the trap should be an  
accept code (2xx) so that the text is not passed to the user by  
default if the smarthost MTA is non-conforming.
-- Dan Oetting
(sent to the list this time)

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