When you recieve an email, you receive more than just the message. The email comes with headers that carry important information that can tell where the email was sent from and possibly who sent it. For that, you would need to find the IP address of the sender. The tutorial below can help you find the IP address of the sender. Note that this will not work if the sender uses anonymous proxy servers.
First of all, the IP address is generally found in the headers enclosed beween square brackets, for instance, [184.108.40.206]
Finding IP address in Gmail
1. Log into your Gmail account with your username and password.
2. Open the mail.
3. To display the email headers,
* Click on the inverted triangle beside Reply. Select Show Orginal.
4. manually find the IP address,as below
5. Look for Received: from followed by the IP address between square brackets [ ].
Received: from [220.127.116.11] by web4587.mail.***.yahoo.com
6. If you find more than one Received: from patterns, select the last one.
7. Track the IP address of the sender