Re: [exim] SMTP connection lost

On Mon, Aug 9, 2010 at 11:21 PM, r00f <r00f@???> wrote:
> Well, thank you for tip but looks like ECN wasn't enabled on that host
>
> #sysctl  -A | grep ecn
> net.ipv4.tcp_ecn = 0

I'm having an issue with a particular site being unable to send emails
that are larger than about 40K. And same configuration here, ECN not
enabled on either the load balancers nor the mail servers.

> Servers negotiate TCP session with MSS 1360. Then they start SMTP session,
> which goes normal during HELO. But when the sending server sends me
> message
> headers, I receive:

I'm having trouble with one site sending to my exim servers. They use
a Barracuda firewall. We have lots of people who send to us, and they
send out to lots of people. We just experience problems when he's
sending email to me. On my side, I see large gaps inbetween packets
that are sent. On their side, they see lots of TCP retransmissions.
It appears that, for those retransmitted packets, my side never gets
that first packet.

The MTU is 1390 bytes for this particular host (seems to be 1420 for
most everybody else). I can find nothing that is causing this. If
you find anything in your case, please do detail it as it could be
related to my case.

--
Regards...      Todd
I seek the truth...it is only persistence in self-delusion and
ignorance that does harm.  -- Marcus Aurealius