Daryl Banttari ( )
Mon, 24 Mar 1997 19:14:33 -0600

Jeff Woods wrote:
> At 06:57 PM 3/23/97 -0600, [Daryl] wrote:
> >I've been following this spammer thread with some interest.
> >Here's an idea:
> >
> >Set up a machine as a mail forwarder (only), and point MX to it. Use
> >only a hosts file for name resolution (disable DNS) so that the only
> >machine the forwarder can look up by name is the "real" mail server.
> Duh...... Why couldn't I just add an option in the core router's filter
> table to block port 25 access and leave it on a single machine? Since POP3
> access is on a different port, it could be done without the mess, no?
> Or am I missing something?

My understanding of the spam attack is that someone makes an SMTP
connection to your mail server and sends an email with a much of
addresses on the "RCPT To:" line, which is then expanded into a whole
bunch of emails the mail server dutifully sends out to the 'net. Or, it
could be a bunch of individual emails; either way, they get YOUR server
to do THEIR dirty work (i.e., mail spamming people) for free, and
without any authentication needed. If my understanding is correct, POP3
is used for reading/deleting mail in a mailbox; outgoing mail is done
through SMTP. If it's not correct, feel free to enlighten me.


-- +|Daryl S. Banttari, CNE|||"Talk does not cook rice" - Chinese proverb|'Good things come to those who wait, but only the things left by | those who hustle.' - Abe Lincoln|'A candle loses nothing by lighting another candle' - Fr. James Keller|'There is a diminishing return on caution' - Me+