"If you need to investigate the origin of an email message, all the
information that you require in order to do is right there, in the message
itself, in a section called the header. Trouble is, most email programs don't
display the header information by default. And even if they did, it would be
difficult to understand because it's not really structured in a way that most
people can comprehend. However, this free online tool makes it all very easy.
" Just the thing for spotting possible phishing email or other fake email
supposedly from your friends.
http://www.techsupportalert.com/content/free-tool-analyses-email-header-show-route-taken.htm