For Gmail Accounts:-
Log into your Gmail account with your username and password.
*Open the mail.
*To display the email headers,
*Click on the inverted triangle beside Reply. Select Show Orginal.
*Look for Received: from followed by the IP address between square brackets [ ].

Received: from [69.138.30.1] by web31804.mail.mud.yahoo.com
*If you find more than one Received: from patterns, select the last one.

Finding IP address in Yahoo! Mail

*Log into your Yahoo! mail with your username and password.
*Click on Inbox or whichever folder you have stored your mail.
*Open the mail.
*If you do not see the headers above the mail message, your headers are not displayed. To display the headers,
**Click on Options on the top-right corner
*In the Mail Options page, click on General Preferences
*Scroll down to Messages where you have the Headers option
*Make sure that Show all headers on incoming messages is selected
*Click on the Save button
*Go back to the mails and open that mail


*Look for Received: from followed by the IP address between square brackets [ ]. Here, it is 202.65.138.109.That is be the IP address of the sender.If there are many instances of Received: from with the IP address, select the IP address in the last pattern. If there are no instances of Received: from with the IP address, select the first IP address in X-Originating-IP.