_:n29aa153e314243d4bed9ac72351d79f1xb4
<http://schema.org/text>
"Testing SMTP relay is very easy, and simply requires a small change to the above commands.  See below:\n\nehlo mydomain.com \nmail from:<martin9700@mydomain.com> \nrcpt to:<recipient@someotherdomain.com> \ndata \nThis is a test, please do not respond \n. \nquit\n\n\nSee the difference?  On the RCPT TO line, we're sending to a domain that is not controlled by the SMTP server we're sending to.  You will get an immediate error is SMTP relay is turned off.  If you're able to continue and send an email, then relay is allowed by that server."
<https://frontend.spiceworks.com/how_to/11-test-email-flow-using-smtp-commands?from_group=240>