Hi. This is the qmail-send program at servidor.de.correo.org…
I’m afraid I wasn’t able to deliver your message to the following addresses.
This is a permanent error; I’ve given up. Sorry it didn’t work out.

ip.ip.ip.ip does not like recipient.
Remote host said: 550 #5.1.0 Address rejected webmaster@dominio.com
Giving up on ip.ip.ip.ip.

Este mensaje de error se genera cuando se envía un correo a una dirección que NO existe en el servidor de correo.