My sendmail server occasionally fails at delivering an email. I get a Service unavailable error:

Feb  7 23:45:01 ip-10-101-xx-xx sm-mta[3838]: q17Nj0RQ003836: to=<xxxx@xxx.edu>, ctladdr=<www-data@ip-xxxxx.ec2.internal> (33/33), delay=00:00:01, xdelay=00:00:01, mailer=esmtp, pri=121203, relay=smtp.xxxx.xxxx.edu. [144.92.xx.xx], dsn=5.0.0, stat=Service unavailable

My question is how can I tell if the service at my end was down or the service at the recipient? If it's my problem, how can I solve it?

I'm asking because I'm getting a lot of these errors lately...

  • Are there more logs available? – Karlson Feb 22 '12 at 15:58
  • Send us the output of grep q17Nj0RQ003836 /var/log/mail.log – adamo Feb 23 '12 at 8:33

From your log line: relay=smtp.xxxx.xxxx.edu. [144.92.xx.xx]

That remote server returned a permanent (500) SMTP error code, and so your server will generate a bounce (a Delivery Status Notification). It would be interesting to see what the actual error on the remote server was - usually Sendmail gives a more informative error message and DSN= number.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.