Subject: Re: SPAM Alert: Email Address Harvesting
To: None <current-users@netbsd.org>
From: Wolfgang S. Rupprecht <wolfgang+gnus20040105T131213@dailyplanet.dontspam.wsrcc.com>
List: current-users
Date: 01/05/2004 13:30:33
woods@weird.com (Greg A. Woods) writes:
> Note that if you were to break Postfix's SMTP compliant behaviour and
> cause it to drop the connection immediately when the specified pattern
> is matched then you _might_ stop some of the spam from burning up some
> of your bandwidth some of the time, but you would create a situation
> where any spam sent through a real mailer would result in endless
> retries of the same message over and over again eating up MUCH more
> bandwidth until days later when hopefully the sending mailer gives up
> and tries to bounce it back to the sender.

There is one situation where postfix will drop the connection.  If the
remote spamware fails to take note that the "RCPT TO:" was declined
and goes on the DATA phase anyway.  At that point postfix patiently 
nak each line with: 

    554 Error: no valid recipients;

If the other side continues anyway it emits the following and closes
the tcp connection.

    221 Error: I can break rules, too. Goodbye.

Well, I laughed when I saw it.

-wolfgang
-- 
Wolfgang S. Rupprecht 		     http://www.wsrcc.com/wolfgang/
       The above "From:" address is valid.  Don't mess with it.