Author: Scott Neader Date: To: exim-users Subject: Re: [exim] SMTP command timeout on connection - how to troubleshoot
I was able to get the remote mail server admin to send me a packet capture
in .pcap format (if anyone wants to see it, I'd be glad to share, nothing
confidential in the cap).
What I see is that our Exim server sends the "250 OK id=xxxxxxx" message
just fine, and within a few ms, their server sends an ACK packet.
Here's the funny part... 120 seconds later, my Exim server sends a "421
my.servername.net: SMTP comamnd timeout - closing connection" packet, and
their server sends the ACK for that also, then my server sends the "FIN,
ACK", and their server sends the ACK, and the connection is closed.
Any ideas what is going on?
- Scott
On Fri, Feb 17, 2012 at 3:11 PM, Scott Neader <scott@???> wrote:
> One particular remote mail server seems to be having problems delivering
> mail to one of my local servers running Exim. The server reports that it's
> running "EdgeWave mag2700" if this matters.
>
> I have in my Exim config:
>
> smtp_receive_timeout = 120s
> log_selector = +subject +arguments +received_recipients
>
> Here is a log snippet, redacted:
>
> 2012-02-17 14:22:52 H=sbox.example.net [1.2.3.4] Warning: Sender rate 1.3
> / 1h
> 2012-02-17 14:22:53 1RyUKT-0003th-B6 <= jspringsteen@??? H=
> sbox.example.net [ 1.2.3.4 ] P=esmtp S=43627
> id=00e901ccedb1$f272dcf0$d75896d0$@??? T="test 1A" for
> jthein@???
> 2012-02-17 14:24:53 SMTP command timeout on connection from
> sbox.example.net [ 1.2.3.4 ]
> 2012-02-17 14:24:53 H=sbox.example.net [ 1.2.3.4 ] Warning: "Connection
> Ratelimit - sbox.example.net [ 1.2.3.4 ] because of notquit:
> command-timeout (1.3/1h max:1.2)"
>
> Note, that even though it says "connection ratelimit" I have this server
> set to disregard ratelimits, for troubleshooting purposes, so we are
> continuing to accept connections from them, with no rate limit.
>
> You can see that the remote server connects, provides the email headers,
> then seems to do nothing for 120 seconds, at which time we disconnect them.
>
> What are my options for troubleshooting? Of course the remote mail server
> admin feels that it's OUR problem. It's hard to refute that, when I have
> 2977 other timeout messages in my log (this 1.2.3.4 server accounts for 146
> of them). Of course, probably a lot of those are spammers.
>
> - Scott
>
