someone is harassing me, what would I do??except report abuse?

Question

There is a nasty guy harrasing me all the time on my mail, He gives me true information about me which indicates that he knows me
I want to know who is this guy and make him payback
so plz I dopn't want these funny answer telling me to report abuse
Coz I want to know who is this guy for real
Professional answer gets my vote
thx

Answer 1

here is a start
http://theemailfinder.com/?hop=weblookup

http://www.superdetective.net/
good luck