Just a thought... I had a problem like this several years ago when I
have TCP Explicit Congestion Notification:
http://en.wikipedia.org/wiki/Explicit_Congestion_Notification
turned on on a Linux host running Exim and the remote end was a Sun
Solaris box that didn't understand ECN properly... there also used to
be problems with some routers (with old firmware) not handling ECN
properly...
Mike
On 09/08/2010 13:04, r00f wrote:
> Hi there.
>
> I constantly receive errors with some servers and can't accept or send
> mail to them.
> In log this looks like:
>
> SMTP connection from forward14.mail.yandex.net [95.108.130.92] lost while
> reading message data (header)
>
> This results in two porblems (maybe more):
> 1) I cannot send to servers, who have sender callout verification enabled
> (if they are in problem group)
> 2) I cannot receive messages from servers in problem group
>
> I've read lots of forums about that problem.
> First, I must say that lots of logs posted to forums contatin that same
> Yandex servers.
> Second, I've tried to change my MTU and disable DNS checks - still no
> success.
> Third, the traceroute to the server mentioned looks quite strange - it is
> not traceable form my server, but it's ok from my home PC.
> It seems to be blocking ICMP from some network, and AFAIK this can cause
> MTU traceback not working. But, is Exim trying to make MTU trace?
> If it is, is there any way to avoid that for some hostlist?
>
> Any thoughts about this would be much appreciated.
>
> P.S. atm I don't have any tcpdump log, but as soon as Yandex' MTA retries
> I'll get it and post here if needed.
>
