Mail from this sender has been blocked. IB720

[sggreener]

I've set up a new email account on my website using roundcube.

When I send an email to someone the email bounces with the following message:

Delivery to the following recipients failed permanently:

   * [email protected]

Reason: There was an error while attempting to deliver your message with [Subject: "xxxxxx"] to [email protected]. MTA sg2nlsmtp04.shr.prod.sin2.secureserver.net received this response from the destination host IP - XXX.XXX.XXX.XXX -  550 , 550-5.7.0 Mail from this sender has been blocked. IB720

Any idea what IB720 is and how it can be fixed?

regards
Simon

[SKaero]

The server that is sending the email is on spam blacklists https://mxtoolbox.com/SuperTool.aspx?action=blacklist%3asg2nlsmtp04.shr.prod.sin2.secureserver.net&run=toolpage There isn't much you can do about that, I would recommend contacting your email provider since they should be keeping there server off of the blacklists.