From: DJ Lucas (djlucasit.com)
Date: Mon Dec 01 2008 - 22:22:40 CST

• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Roman Medina-Heigl Hernandez wrote:
> Yes, you're right (I trust you! :-)). I did a quick search in my inbox and
> found an example: notices from Ubuntu bug tracking system ("Launchpad" at
> canonical.com) use that (poor) technique. But I'm wondering:
> 1) How often could you find this "nasty errors" (yes, difficult question;
> impossible to answer, I'd add)
> 2) How important are this kind of "notices"...
>
> Although it's a personal opinion, it seems that I can afford "loosing" such
> mails... On the other hand, perhaps they're identifiable by other means, I
> mean, headers, such as:
>
> Return-Path: <bouncescanonical.com>
> X-Original-To: romanrs-labs.com
> Delivered-To: romanrs-labs.com
> ...
> Received: from gangotri.ubuntu.com (localhost.localdomain [127.0.0.1])
> by gangotri.ubuntu.com (Postfix) with ESMTP id 0C222318376
> for <romanrs-labs.com>; Fri, 28 Jul 2006 04:10:09 +0100 (BST)
> From: RoMaNSoFt <romanrs-labs.com>
>
Maybe I'm incorrect, but I believe there was a subtle misunderstanding
in the above conversation. The From: header is not the same as MAIL
FROM: command in smtp transaction. MAIL FROM for this message was
bouncescanonical.com. Feel fee to find that message in your logs and
verify. Anyway, the Postfix directive you are looking for is
"reject_unauthenticated_sender_login_mismatch".

http://www.postfix.org/postconf.5.html#reject_unauthenticated_sender_login_mismatch

That said, cheap web scripts often do use the recipient's address in the
transaction. Latest complaint I had was from some star rewards thing
for frequent visits to a restaurant (for which I promptly replied:
"choose a different restaurant" ;-) ).

Take the following two manual transactions as an example with the smtpd
sender restriction above (only slightly altered to avoid giving away
unnecessary info and posting a real address in plain text on the internet):

[djname25 ~]# telnet mail.lucasit.com 25
Trying 192.168.xxx.xxx...
Connected to mail.lucasit.com.
Escape character is '^]'.
220 postal.lucasit.com ESMTP Postfix
ehlo somehost.lucasit.com
250-postal.lucasit.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
MAIL FROM: nouserlucasit.com
250 2.1.0 Ok
RCPT TO: nouserlucasit.com
553 5.7.1 <nouserlucasit.com>: Sender address rejected: not logged in
quit
221 2.0.0 Bye
Connection closed by foreign host.
[djname25 ~]#

[djname25 ~]# telnet mail.lucasit.com 25
Trying 192.168.xxx.xxx...
Connected to mail.lucasit.com.
Escape character is '^]'.
220 postal.lucasit.com ESMTP Postfix
ehlo somehostlucasit.com
250-postal.lucasit.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
MAIL FROM: bouncessomehost.lucasit.com
250 2.1.0 Ok
RCPT TO: nouserlucasit.com
450 4.2.0 <nouserlucasit.com>: Recipient address rejected: Greylisted,
see http://postgrey.schweikert.ch/help/lucasit.com.html
quit
221 2.0.0 Bye
Connection closed by foreign host.
[djname25 ~]#

HTH

-- DJ Lucas

--
This message has been scanned for viruses and
dangerous content, and is believed to be clean.

• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]