Wow, yes apparently when somebody sends you email from Yahoo or Hotmail you can still see their IP. Gmail hides it though. Amazing, if somebody sends you email from Hotmail/Yahoo, enable advanced header option in your email client as bkshres had mentioned and find either Received: from [xxx.xxx.xxx.xx] or X-Originating-IP: [xxx.xxx.xxx.xx] tags where xx.xxx.xxx.xxx is the IP of the sender. Then to track down that IP, use this url http://whois.domaintools.com/xxx.xxx.xxx.xx ( ofcourse replacing xxx.xxx.xxx.xx with the real IP :)