add mail relay server via control panel?

    I am not familiar with postfix and smarthost, but I think your configuration should be something like this:


    In your case the MASTER CF_PARAMETERS can be empty.


    What is logged in /var/log/mail.log after sending an email?


    Code
    1. echo "This is a test." | mail -s "My great test subject" -a "From: sender@your-domain" recipient@your-external-test-domain

    Seems not commenting the MASTER CF_PARAMETERS was the issue. I've commented them out and now it's working.

    Thank you very much for the help. :)