How to find the original IP address on an email
Occasionally, the need arises to find the IP address on an email someone has sent you. Being able to find the IP address of where an email you have received originated from helps allow you to authenticate that it is coming from who it says it is, and it is also very helpful if you wish to, and have the ability to, block contact from a specific IP address. As there are so many email service providers available, and each have slight differences in the process, this will focus on Yahoo mail and Gmail as they are the most common at this time.
In Yahoo mail, it is easiest to find the IP address in the beta version of their email, you can switch from one version to the other in seconds with one click. Double click the email you want to open so it will appear in a new tab. Look at the top right where the sender/recipient information is and look for a drop down menu. It should say “Standard Header” as that is the default setting. Open the drop down menu and select the option “Full Header.”
Once you have done that, you will see maybe twenty lines of text on average. What you are looking for is “Received From”, and the particular one you want is the received from line that appears the furthest down in the block of text. That is the original sender of the email, and with that you will see the IP address for the location the email was sent from. An IP address will look something like 12.345.678.901. In the text field, it will look something like this:
Received: from blah ([12.345.678.901]) by mx.google.com with ESMTP id hi3si7462wxd.2009.10.05.38
Wed, 05, Nov 2009 18:36 -0700 (PDT)
The above example is random numbers that actually reflect no actual account, but it serves to illustrate more clearly exactly what you need to locate. The IP address appears in the first line of text In parenthesis and brackets.
In Gmail the process is a little simpler. First open the email, then locate the arrow pointing down just to the right of the “Reply” button. Click the arrow, and from the drop down list click on “Show Original.” Once you have done that, the process of locating the IP address is the same as was used to find the IP address in Yahoo mail.
People with blogs usually find this quite helpful as well if they have a feature that allows email to be forwarded to them. Parents have used this to see where their kids are emailing them from, and sometimes people use it to see if people are being straight with them. For instance, someone sends you an email and says they had to leave work to pick up their kid or something, and they are contacting you from home and are therefore unable to help you. You can compare the IP on that message to the IP from a previous email you do know they sent from work and tell if they are lying or not. What you use it for is your business, it is just a means to verify information.