Re: rfe: automagic open relay message refusal?

[Arnt Gulbrandsen <arnt@gulbrandsen.priv.no>]

"Benjamin C.R. LaHaise" <blah@kvack.org>
> Where connect and check involves opening an SMTP session to the remote
> server and verifying that it does not relay mail for anyone.

Have a look at this:

[arnt@disorder arnt]$ telnet bra.gulbrandsen.priv.no 25
Trying 212.125.101.197...
Connected to bra.gulbrandsen.priv.no (212.125.101.197).
Escape character is '^]'.
220-bra.gulbrandsen.priv.no Zmailer 2.99.54 #1 ESMTP, no spam welcome
220 Local time in Augsburg, Germany is Thu, 14 Jun 2001 20:03:34 +0200.
helo disorder.primate.net
250 bra.gulbrandsen.priv.no Hello disorder.primate.net
mail from: <hermes@hermes.com.cn>
250 2.1.0 Sender syntax Ok
rcpt to: <arnt@gulbrandsen.priv.no>
250 2.1.5 Recipient address syntax Ok; rcpt=<arnt@gulbrandsen.priv.no>
data
354 Start mail input; end with <CRLF>.<CRLF>
From: hermes@hermes.com.cn
To: arnt@gulbrandsen.priv.no
Subject: test
 
test
.
250 2.6.0 message accepted; into freezer[1] area
quit
221 2.0.0 bra.gulbrandsen.priv.no Out
Connection closed by foreign host.
[arnt@disorder arnt]$ 

Spot the "freezer" mention. That message is thrown straight into
/var/spool/postoffice/freezer through the magic of Zmailer's smtp-policy
code.

What would you do if I (= that server) sent you mail? Would you conclude
that, since I answer "250" to a lot of RCPT TO arguments, I'm is an open
relay, and reject my mail?

Would you wait to see if I actually do relay?  What would you do if,
during your open-relay probe, _I_ started testing whether _your_ server is
an open relay?

--Arnt
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