Saturday, July 9, 2016

Client host rejected: Access denied

Yesterday I noted that lino-framework.org is not sending emails any more. It turned out that Elisa had blocked it on their SMTP server. When trying to submit a message, I get:

host smtp.elisa.ee[194.150.66.204] refused to talk to me: 554 5.7.1 <unknown[194.204.31.42]>: Client host rejected: Access denied)

Now I am trying to figure out why. It seems that this is because my server had been sending spam. Looking into my mail.log, I choose the following case:

Jul  3 06:32:33 vps postfix/smtp[32614]: 899E82A44B8: to=<ayaty@drxunchdv.org>, relay=smtp.elisa.ee[194.150.66.204]:25, delay=216939, delays=216908/0.04/30/0.13, dsn=4.1.2, status=deferred (host smtp.elisa.ee[194.150.66.204] said: 450 4.1.2 <ayaty@drxunchdv.org>: Recipient address rejected: Domain not found (in reply to RCPT TO command))

By grepping for 899E82A44B8, I see that the earliest entries are:

$ sudo grep 899E82A44B8 /var/log/mail.log.1
Jun 30 18:16:54 vps postfix/cleanup[32082]: 899E82A44B8: message-id=<20160630151654.899E82A44B8@lino-framework.org>
Jun 30 18:16:54 vps postfix/qmgr[3362]: 899E82A44B8: from=<>, size=33933, nrcpt=1 (queue active)
Jun 30 18:16:54 vps postfix/bounce[32081]: 71E8A2A69D9: sender non-delivery notification: 899E82A44B8
Jun 30 18:16:54 vps postfix/smtp[32080]: 899E82A44B8: host smtp.elisa.ee[194.150.66.204] said: 450 4.1.2 <ayaty@drxunchdv.org>: Recipient address rejected: Domain not found (in reply to RCPT TO command)
...

Hm… I lack experience in finding out the guilty from those logs. Reading the comments in this thread, I suspect a WordPress site which I installed a few months ago and which is not being used anymore. So just in case I simply uninstall WordPress and PHP:

$ sudo aptitude remove wordpress
$ sudo aptitude remove php5 dokuwiki mediawiki php-wikidiff2

I hope for Andi’s help on Monday for analyzing the log files in order to make sure whether this is a plausible explanation.

Supervisor

So now I can continue to get linod running using Supervisor.

I used the recommended way described on the installation page:

$ easy_install supervisor

Though after reading this I think that I should have preferred pip over easy_install

So this installed the binaries to my virtual environment at /usr/local/pythonenv/demo.

I created the config file /etc/supervisord.conf as instructed.

I learned that the message unix:///tmp/supervisor.sock no such file means simply that the supervisord daemon is not running.

I downloaded the Debian startup script to /etc/init.d/supervisord and adapted two lines:

DAEMON=/usr/local/pythonenv/demo/bin/$NAME
DAEMON_ARGS="-c /etc/supervisord.conf --pidfile ${PIDFILE}"

And then (thanks to this for the hint) registered it as a service:

$ sudo update-rc.d supervisord defaults