Thanks Alien - I tried that and when I send emails (even when I change the "sent from") the receiver sees :

"From: <img id="P___1520256335" webimdisplaystyle="inline" style="display: none;"> chidgeychris******.com on behalf of Chris Chidgey (chris@thelifesettlementnetwork.com)"

This is the case for Outlook 2007 and Hotmail.