It would be really nice if all email client stop sending IP address for security. Just seeing this thread I tried to send email from my yahoo email to hotmail email and vice versa. I can still see IP address there. When you send email from Yahoo.com: Received: from [xx.xxx.xxx.xxx] by web30208.mail.mud.yahoo.com via HTTP; Sun, 10 Dec 2006 11:47:20 PST When you send from hotmail: X-Originating-IP: [xx.xxx.xxx.xxx] where this xx.xxx.xxx.xxx is the IP address of sender's computer. To view this, you have enable advanced header option in hotmail and similar setting in yahoo or any email client... seems like web based email clients still send originating IP address unless there is an option to not send originating IP.