SMTP mail reception problems: timeout or CRLF?

[ranageman]

Hi,

I get repeated log entries for qmail like this:

qmail-queue: drweb-qmail[3511]: possible qmail-smtpd exited by timeout, reset connection or with "See http://pobox.com/~djb/docs/smtplf.html."

This can either be a remote mail client problem, as explained by the link, or it can be a real timeout.

The customer mail client is:
X-Mailer: Lotus Notes Release 6.5.2 June 01, 2004

The sender gets a delivery failure notice, with either a blank message or just a timeout. But it takes a long time due to retries.

So the question is:
- how can I tell if it was a real timeout or the CRLF problem?
- how can I set logging options to give remote IP in the logs. This would help to see when / who is having a problem
- is there any workaround?

regards,

/ranageman

 

[ausip]

I am having the same troubles with Plesk 8.2 on FC6

The problem existed on my 7.5 server. I hoped 8.2 would rectify the problem, but to no avail.

I have done some research, although I do not have the links in front of me. One option was to patch Qmail during a compile. The other option was to run a second MTA on the server that would repair bare LF or bare CR and then pass the mail to QMail.

Neither of these options seem ideal to me.

Does anyone have any ideas.

 

[ranageman]

I finally fixed my problem - it was actually a timeout.

This is apparently because qmail-smtpd asks for "remote info". If
the remote server does not serve this within 30s, qmail times out
and continues. But if the remote end only waited 30s too....it times out!

This remote info fetching is useless and can be switched off: See "man tcp-env".

Here's another guy with the problem.
http://www.ornl.gov/lists/mailing-lists/qmail/2003/10/msg00426.html

The answer is to edit /etc/xinet.d/smtp_psa and add -R to the start
of the server_args line:

[root@39151 xinetd.d]# cat smtp_psa
service smtp
{
socket_type = stream
protocol = tcp
wait = no
disable = no
user = root
instances = UNLIMITED
server = /var/qmail/bin/tcp-env
server_args = -R /var/qmail/bin/relaylock /var/qmail/bin/qmail-smtpd /var/qmail/bin/smtp_auth /var/qmail/bin/true /var/qmail/bin/cmd5checkpw /var/qmail/bin/true
}

Then issue "xinetd restart" and you are off again...

That worked for me anyway.....

RM

 

[ausip]

Thanks for the Reply.

This didn't seem to work for my problem. I also tried -Rt0 as found in another post.

Do you have any other ideas?

Where do I find the qmail-smtp logs. I looked through /usr/local/psa/var/log/maillog but this doesn't seem to contain info regarding the 451 bounce back messages. Do you know where I can find or enable this level of logging.

Hope someone has some further ideas.

Thanks
Paul.

 

[ranageman]

No other ideas, sorry.

And I have also looked in vain for where to enable extended logging for qmail, as asked in my first post. Let us know if you ever find out!

RM

 

[ausip]

I have found my problem. It is purely due to the fact that Qmail will not accept mail with Bare CR's or LF's. I used a HEX editor to search for bare characters and manually modified them. The emails were then allowed through.

Back to finding a way to either parse the emails and modify the HEX CR's and LF's or to make Qmail allow them through.

THanks for your help with this.