[TriLUG] Email sending problem....

[Mike Johnson]

Kevin - The Alchemist - Sonney [alchemist at darkcanvas.com] wrote:
 
> [15:01:20 alchemist]$ telnet users.sourceforge.net 25
> Trying 216.136.171.198...
> Connected to users.sourceforge.net.
> Escape character is '^]'.
> 220 usw-sf-list1.sourceforge.net ESMTP Exim 3.31-VA-mm2 #1 Mon, 10 Sep
> 2001 12:06:47 -0700 - SF usw-list mm5
> HELO darkcanvas.com
> 250 usw-sf-list1.sourceforge.net Hello midgard.webslingerz.com
> [66.45.6.19]
> MAIL FROM:<alchemist at darkcanvas.com>
> 250 <alchemist at darkcanvas.com> is syntactically correct
> RCPT TO:<ksonney at users.sourceforge.net>
> 250 <ksonney at users.sourceforge.net> is syntactically correct
> DATA
> 354 Enter message, ending with "." on a line by itself
> Subject: test message
> 
> This is a test message
> .
> 550-Envelope sender verification failed
> 550 rejected: Cannot route to envelope sender
> <alchemist at darkcanvas.com> (The envelope sender does not exist
> according to your mail server when it was asked): response from
> mail.darkcanvas.com [66.45.6.19] after "MAIL FROM: <>" was "554
> buildaddr: no host". This does not help fight spam effectively, breaks
> RFCs, and prevents you from getting bounces so we can't accept mail
> from you
> QUIT
> 221 usw-sf-list1.sourceforge.net closing connection
> Connection closed by foreign host.
> 
> Ah! So sourceforge check to be sure it's a valid sender by
> back-tracking to midgard.darkcanvas.com and trying to send mail - but
> they're either ignoring the MAIL FROM listed above, or they are
> expecting a header I'm not setting.

Well, it's not a header thing.  They are looking at your MAIL FROM
line (alchemist at darkcanvas.com) and connecting to your mail host
(they look up the MX record for darkcanvas.com).  When doing
this lookup:
[mike at fiend mike]$ host -t mx darkcanvas.com
darkcanvas.com          MX      10 mail.darkcanvas.com

So, they connect to mail.darkcanvas.com (which resolves to
66.45.6.19) and see if they can send you a message.  It
seems what they're after is to verify they can at least send
your -server- a bounce.

Basicly, they're ignoring any header you can set.  It's your
sendmail config that's the problem.  Since you can't send
the MAIL FROM: <> to mail.darkcanvas.com, they're not gonna
accept your message.

I'm sure they have their reasons for doing this (seems kinda
silly to me), but that's what they're doing.  You'll have
to work around it.

Mike
-- 
Never trust a man who puts anything other than a finger up his nose. - _Snatch_