Duplicate message troubleshooting

[Jeff Rush]

Nicolas Bougues wrote:
> 
> Here is the kind of things my SMTP relay logs while talking to openmoko's list 
> server :
> 
> Jul 24 18:46:21 cassis postfix/smtp[9586]: 7E28BE0BA0: 
> to=<community at lists.openmoko.org>, 
> relay=sita.openmoko.org[88.198.124.203]:25, delay=12360, 
> delays=12279/0.16/0.15/80, dsn=4.4.2, status=deferred (
> conversation with sita.openmoko.org[88.198.124.203] timed out while sending 
> end of data -- message may be sent more than once)
> 
> There is a fair amount of those messages concerning openmoko, and just one or 
> two regarding other destinations (out of 25000+ mails relayed yesterday).
> 
> I only posted once or twice to the list before, and no such behavior was 
> encountered.
> 
> Unfortunatly, I don't have further SMTP traces.
> 
> Could there be some connectivity problem, maybe firewall related, on 
> openmoko's side ?

The problem is their SMTP server is taking its own sweet time recognizing the
end-of-message sequence, so peer MUAs are starting to timeout instead.  Here
is a manual session:

jeff at kim ~ $ telnet sita.openmoko.org smtp
Trying 88.198.124.203...
Connected to sita.openmoko.org.
Escape character is '^]'.
220 sita.openmoko.org ESMTP Exim 4.50 Wed, 25 Jul 2007 10:37:31 +0200
EHLO taupro.com
250-sita.openmoko.org Hello adsl-68-95-135-33.dsl.rcsntx.swbell.net [68.95.135.33]
250-SIZE 52428800
250-PIPELINING
250 HELP
RCPT: test at openmoo.org
500 unrecognized command
MAIL FORM
500 unrecognized command
MAIL FROM:<jeff at taupro.com>
250 OK
RCPT TO:<test at openmoko.org>
550 unknown user
RCPT TO:<community at lists.openmoko.org>
250 Accepted
DATA
354 Enter message, ending with "." on a line by itself
Date: 25 Jul 2007 03:34:00
From: jeff at taupro.com
To: community at lists.openmoko.org
Subject: Diagnostic Message

This is a probe message to diagnose the SMTP problems.  Please ignore.

.
(very long idle interval of 5 minutes or so)
250 OK id=1IDcPE-0002wr-QA


It may be running off to validate the sender domain name to prevent spam, but
is taking too long I think - perhaps an inefficient DNS arrangement.  There
are issues with their DNS, as this validator shows:

    http://www.dnsstuff.com/tools/dnsreport.ch?domain=openmoko.org

with the biggest problem being stealth NS records with leakage, which can
wreak havoc with timeouts.

And yes, I copied the -owner of the community list.

-Jeff