Whenever you receive an email, there is a lot more to it than meets the eye. While you typically only pay attention to the from address, subject line and body of the message, there is lots more information available 'under the hood' of each email which can provide you a wealth of additional information.
You really wouldn't ever need to look at an email header unless you suspect an email is a phishing attempt or spoof, if you want to view routing information on the email’s path, ot when you're a curious geek. Regardless of your reasons, reading email headers is actually quite easy and can be very revealing.
(via Look At This...)The Presurfer