How To Find the Sender's Original IP Address Using Email Message Headers

So you'd like to to find out just who is sending those email love letters, determine the sender of a blackmail message, or just root out the source of a virus emailed to you. This article will teach you how to use "Email Headers" to backtrack and find the original sender's IP address. Don't worry, it's not rocket science.
Email messages, as in the case of their non-electronic cousins, have "envelopes" of a sort. In the case of email the envelope is composed of a series of "Headers". These are just a series of lines of characters which precede the actual email message. Email programs such as Outlook do not normally display these Headers when displaying a message. From these Headers however, the email program is able to extract important information about the message, such as the message encoding method, the creation date, the message subject, the sender and receiver, etc.
Moreover, just as a postal envelope contains an address, a return address and the cancellation stamp of the post office of origin, an email message in these "Headers" carries with it a history of its journey to your email inbox. Because of this, it's possible to determine the original IP address of the sender.
Since email programs do not normally display these Headers, we must first learn how to display them. Depending on the program, this is done in a variety of ways. The following sequence details the way to do this using the Windows default email program, "Outlook Express". First, select "Properties" from the "File" Menu, or just press ALT+Enter. Next, select the "Details" tab.

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