Re: [exim] SMTP connection lost after final dot

On Wed, Dec 5, 2012 at 7:22 AM, Terry (1stKMH) <terry@???> wrote:
> I did as you said Todd but the tests just zoom through in a fraction of a
> second.

That's good actually.

> I am still getting lost connections though and I am a bit stumped to be
> honest all logs look happy as far as I can see. Also did a complete server
> reboot
>
> +++ 1TgGfR-0004Zf-AQ has not completed +++
> 2012-12-05 15:17:20 1TgGfR-0004Zf-AQ H=mx1.thedmcgroup.co.uk (rowcol.co.uk)
> [92.60.107.247] Warning: spam-score-int: -25 (--). spamreject: 100.
> 2012-12-05 15:17:20 1TgGfR-0004Zf-AQ SA: Debug: SAEximRunCond expand
> returned: '0'
> 2012-12-05 15:17:20 1TgGfR-0004Zf-AQ SA: Action: Not running SA because
> SAEximRunCond expanded to false (Message-Id: 1TgGfR-0004Zf-AQ). From
> <service@???> (host=mx1.thedmcgroup.co.uk [92.60.107.247]) for
> david@???
> 2012-12-05 15:17:20 1TgGfR-0004Zf-AQ SMTP connection lost after final dot
> H=mx1.thedmcgroup.co.uk (rowcol.co.uk) [92.60.107.247] P=esmtp

Can you dig in the logs (i.e. not exigrep output) and see where the
initial connection was made? The log messages shown above don't seem
to indicate the actual connection, just the point where it finally
gave up. You might need to add some debug logging in the connect,
mail, and rcpt acl's (won't have a mail queue id, so make sure to log
the sender ip address, $sender_address IIRC) so that you can identify
the timing of this inbound email.

If it was me, I would also start a tcpdump on the server, writing
output to a file in pcap format, for a known IP exhibiting the
symptoms, and then wait for an email delivery to be attempted, then
examine the data in detail. Make sure to use -s0 to not limit the
size of the packet it writes to the file.

Are you sure that you are not blocking all ICMP? If you have all ICMP
blocked at any hop between and including your border and your server,
you break Path MTU Discovery (pMTUd) and then any feedback for sub
1500 byte paths are lost. Your description doesn't sound like it, but
check it any way.


...Todd
--
The total budget at all receivers for solving senders' problems is $0.
If you want them to accept your mail and manage it the way you want,
send it the way the spec says to. --John Levine