A simple trick to trace ip adresses throught mails

for that sign into yahoo mail with ur yahoo id , and u will find "options" on the right hand corner of the page ( also if u click on "mail" on the top left hand side of the page a drop down menu appears , u find options under that as well)

under that click on "general preferences" and then scroll down u will find "messages" under that select " show all headers on incoming messages"

thats it , save it and now when ever u receive any mail u can check out if that ip address belongs to someone u know