Re: [exim] SMTP data timeout

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Autor: Chris Lightfoot
Data:  
Dla: chris1
CC: exim-users
Temat: Re: [exim] SMTP data timeout
On Fri, Nov 03, 2006 at 09:15:42PM +1100, Chris Perry wrote:
    [...]

> I'm thinking now the problem is some specific relationship between the
> UBS server and mine.
>
> I do not know how long the transmission lasts for before failing.
> Anyway of logging that?


an obvious next step would be to use tcpdump to capture
all traffic between their server and yours. something
like,

    tcpdump -i eth0 -w /root/ubs.pcap -s 65535 host 147.60.1.198 and port 25


-- leave that running in a screen somewhere and wait until
the problem recurs (or ask them to send another test mail
if possible). Then take a look at the capture file (most
easily by loading it into ethereal or wireshark or
whatever it's called now). If the MTU explanation is
correct (it seems plausible) what you'll see is that
during the first phase of the SMTP dialogue everything
works OK but once the mail starts to be transmitted you
stop seeing packets (because they exceed the MTU your link
supports).

--
``Solutions are not the answer.'' (Richard Nixon)