Date: Sat, 3 May 1997 15:48:10 +1000 (EST) From: "Daniel O'Callaghan" <danny@panda.hilink.com.au> To: "Jeffrey J. Mountin" <sysop@mixcom.com> Cc: FreeBSD-Hackers@FreeBSD.ORG Subject: Re: SPAM target Message-ID: <Pine.BSF.3.91.970503153737.4479M-100000@panda.hilink.com.au> In-Reply-To: <3.0.32.19970503001034.00bde1cc@mixcom.com>
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On Sat, 3 May 1997, Jeffrey J. Mountin wrote:
> Sendmail should not accept messages that have a blank 'MAIL From:' and we
> will not accept this, missing "@" or missing "." (first checks) and then
> goes on to see if there is a valid TLD after the rightmost "." etc and this
> would block a very large portion of junk mail.
Only until the rats learn the new maze - all they have to do there is to
give a real domain with a fake user. e.g. nobody@lon3.melbourne.telstra.net.
So then you teach sendmail to attempt to verify the user in the From:
MAIL FROM: <danny@hilink.com.au>
{hang on a tick, connect hilink.com.au, HELO, MAIL FROM: <sendmail@here>,
RCPT TO: <danny@hilink.com.au>, 250 RCPT OK, QUIT}
Now, what were you saying...
So then they take the first bunny in the list of spam addresses and make
him the apparent sender. :-(
The only real solution is the removal of SMTP and a new MTP which
requires everyone in the world to have a signing certificate from a
recognised CA.
Danny
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