[plug] sendmail - unexpected close on connection

Russell Steicke r.steicke at bom.gov.au
Fri Feb 7 08:06:03 WST 2003


On Thu, Feb 06, 2003 at 10:45:48PM +0800, ryan at is.as.geeky.as wrote:
> Howdy to the plugged,
> 
> Recently my sendmail server gives the sporadic error as such to incoming messages:
> 
>    ----- The following addresses had permanent fatal errors -----
> <address at goes.here>
>     (reason: 354 Enter mail, end with "." on a line by itself)

Umm, that looks like what the sending MTA would say, quoting text it got
as a reply from the receiving MTA.  So if that above is your from MTA's
logs, that must be an outgoing mail.  Unless things are really weird.

It looks like the two MTAs have gotten out of sync, and one is sending
replies for commands that the other hasn't sent.  The only time that a
354 reply can be sent in SMTP is as a positive reply to the DATA
command.  And below, it seems that the sender has gotten a 250 reply to
the DATA command, which is just not allowed: the RFCs only allow 354 or
various 4xx or 5xx codes.  I think the loss of connection is a side
effect of them being out of sync, where one thinks the conversation has
finished and the other doesn't.

Aside from that, the only thing I can suggest is to grab the SMTP
traffic with tcpdump or ethereal and send a few emails to that address
(with the recipient's consent!) to see if you can capture a failing
transaction.


> 
> The offending receiving sendmail logs show this:
> 
> Feb  6 14:27:11 slowest sm-mta[18429]: h166P36C018429: collect: unexpected close on connection from xxxxxxx, sender=<ryan at is.as.geeky.as>
> Feb  6 14:27:11 slowest sm-mta[18429]: h166P36C018429: from=<ryan at is.as.geeky.as>, size=10, class=0, nrcpts=1, proto=SMTP, daemon=MTA, relay=xxxxxxx [x.x.x.x]
> 
> The sending sendmail log shows:
> 
> Feb  6 14:23:37 localhost sendmail[5409]: h166MxRB005393: mail.slowest.net.: SMTP DATA-1 protocol error: 250 2.1.5 <xxxxxx at xxxxxx>... Recipient ok
> Feb  6 14:23:37 localhost sendmail[5409]: h166MxRB005393: to=<xxxxxxx at xxxxxx>, delay=00:00:37, xdelay=00:00:05, mailer=esmtp, pri=300597, relay=mail.slowest.net. [203.15.140.22], dsn=5.5.0, stat=Remote protocol error
> Feb  6 14:23:39 localhost sendmail[5409]: h166MxRB005393: h166NRRp005409: DSN: Remote protocol error
> 
> I first noticed this type of error many months ago when sending stuff to a friends MDaemon server and assumed it was an MDaemon/Windows specific problem.  Now that my sendmail server has done this I've changed my opinion on the matter.
> 
> Is is possible that my DSL is dropping a few packets at a critical time or is there something more tangible I can pin this on?  If it is just as it says - a loss of connection, I would have though such an error would return transient and not permanent as it does.  Anyone care to comment?
> 
> Thanks,
> 
> Ryan
> 
> 
> 


-- 
Russell Steicke

-- Fortune says:
"What people have been reduced to are mere 3-D representations of their own 
data."
-- Arthur Miller



More information about the plug mailing list