Is not associated with an IP address other then the live servers in Denmark, so no you can't get someones IP from that. When you get mail from MSN live servers you are not connecting to j.henriksen you are connecting to MSN live. Your only way of getting user info from them will be with a court order and even then you may not get it. I'm not even sure if <a class="bbcode_url" href="http://live.dk" target="_blank" rel="nofollow noopener noreferrer">live.dk</a> would keep the information because managing it would cost them money and cause security issues for their users. At the very least they would have whatever information he used to create his account. What is the problem that is causing you to want to track this person down?