This is the error that I saw in the traces:
Aug 23 21:56:33 myhost nullmailer: Starting delivery: protocol: smtp host: mail.nestorurquiza.com file: 1314082502.18221 Aug 23 21:56:33 myhost nullmailer: smtp: Failed: 550 5.7.1 Unable to relay for email@example.com Aug 23 21:56:33 myhost nullmailer: Sending failed: Permanent error in sending the message
This was originated because in etc/hosts I had a line like:
And the SMTP server was not configured to relay to such a thing like myhost.myhost. So just changing it to an authorized domain should fix it right?
Well I kept getting the same error!!!
The reason was queued emails. I was getting from logs also a line like below:
Aug 23 22:26:47 myhost nullmailer: Delivery complete, 42489 message(s) remain.
So deleting the queue made finally the trick:
sudo rm -fR /var/spool/nullmailer/queue/ sudo mkdir /var/spool/nullmailer/queue