Question : Need to check where this person is sending me email.

I have someone who keeps sending me emails from
yahoo.com

How can the location of the person when I am on line or any other solution,

Answer : Need to check where this person is sending me email.

you can report directly to yahoo
http://help.yahoo.com/l/us/yahoo/mail/original/abuse/abuse-16.html

to locate any user you need to get exact ip address.