you can know the mail originating Ip,sender's IP,server details....
kewl isn't it so lez cheq this out!
Follow these steps :
# sign into yahoo
# on the top -right of the page you will see "mail upgrades-options"
# click on options .
# scroll down ..and you will find
general preferences.. select that
# in "General preferences"-- you will find headers under that select second option
as you see in the image.
# now save the changes made go to inbox open any mail
voila
you will find ....
wanna trace that ip?
trace it here |iptracer|