How to troubleshoot this error " timeout after END-OF-MESSAGE"?

[tswmmeejsdad .]

Hi All,

We run a postfix STMP relay for customers. One customer is saying that their application is showing lots of timeouts on their end when it is trying to send emails via our STMP relay. We are also seeing the timeout errors in the mail log (shown below).


How do I troubleshoot something like this?

\\ Logs on postfix SMTP relay

May 19 16:06:50 smtp01 postfix/smtpd[21940]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

May 19 16:10:06 smtp01 postfix/smtpd[21944]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

May 19 16:32:59 smtp01 postfix/smtpd[23036]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

May 19 16:34:06 smtp01 postfix/smtpd[24186]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

May 19 16:53:56 smtp01 postfix/smtpd[24229]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

May 19 17:05:38 smtp01 postfix/smtpd[24190]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

May 19 17:08:02 smtp01 postfix/smtpd[24158]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

Thanks.

Andy

[li...@rhsoft.net]

Am 02.06.2014 00:35, schrieb tswmmeejsdad .:
> We run a postfix STMP relay for customers. One customer is saying that their application is showing lots of
> timeouts on their end when it is trying to send emails via our STMP relay. We are also seeing the timeout errors in
> the mail log (shown below).
>
> How do I troubleshoot something like this?
>

> May 19 16:06:50 smtp01 postfix/smtpd[21940]: timeout after END-OF-MESSAGE from unknown[10.84.72.227]

without knowing anything of your configuration and invironment hard to say
did you miss the welcome message?

http://www.postfix.org/DEBUG_README.html

[Viktor Dukhovni]

On Mon, Jun 02, 2014 at 08:35:25AM +1000, tswmmeejsdad . wrote:

> May 19 16:06:50 smtp01 postfix/smtpd[21940]: timeout after END-OF-MESSAGE
> from unknown[10.84.72.227]

The SMTP client neither closes the TCP socket nor sends QUIT after
completing a message delivery. Fix the client.

--
Viktor.

[tswmmeejsdad .]

Thanks for the info Viktor. That sounds like a rather bold statement and I don't think customers at times are willing to concede that it's something on their end causing it.

Is there anything else that we could do further to prove to the customer that it was their application that as you have said is not closing the TCP socket nor sending QUIT after completing a message delivery?

[Viktor Dukhovni]

On Mon, Jun 02, 2014 at 11:26:47AM +1000, tswmmeejsdad . wrote:

> On Mon, Jun 2, 2014 at 10:19 AM, Viktor Dukhovni <postfi...@dukhovni.org
> wrote:
>
> > On Mon, Jun 02, 2014 at 08:35:25AM +1000, tswmmeejsdad . wrote:
> >
> > > May 19 16:06:50 smtp01 postfix/smtpd[21940]: timeout after END-OF-MESSAGE
> > > from unknown[10.84.72.227]
> >
> > The SMTP client neither closes the TCP socket nor sends QUIT after
> > completing a message delivery. Fix the client.
>

> Thanks for the info Viktor. That sounds like a rather bold statement and I
> don't think customers at times are willing to concede that it's something
> on their end causing it.

No need to be shy about stating the truth.

> Is there anything else that we could do further to prove to the customer
> that it was their application that as you have said is not closing the TCP
> socket nor sending QUIT after completing a message delivery?

A packet capture. Your log excepts are much too short to conclude
that the unterminated connection is from the customer. All I said
was that that SMTP client neither closed the connection, nor sent
QUIT. That SMTP client might be some middle box between you and
the customer, or even some proxy on your own server.

You need to look at the complete logging to determine whether the
log messages in question are a result of a direct connection from
the customer, or mediated in some way.

--
Viktor.

[tswmmeejsdad .]

Hi Viktor,

Terrific advice. Much appreciated.

Cheers.

Andy