When you read the email may be visible only date information, to, cc, bcc, subject and message. In each email sent would include information such as the complete message id, mailers, ip address, and so forth. If you want to know the ip address the email sender and its ISP used tips you can read the following.
1. Login to Yahoo Mail.
2. Select one of the email that you want to check.
3. Click on the link or Full Header, which is located at the bottom right.
4. Locate the "Received: from [...] by."
5. In the example below addressnya IP is 220.127.116.11.
MS Outlook Express:
1. Open Outlook Express program.
2. Right-click on one of the email that you want to check.
3. Click the Properties menu.
4. Click the Details tab.
If you have to get further information ip address you can check the ISP used its city.