Can you do a reverse email address search for free?

I am getting mushy and now getting creepier cards and messages from this email and I want to know who it is. They wont tell me and I am getting freaked!|||it depends on the address if its a admin@yourdomain.com then you can do a whois search and that will track him down for you, but if it is one of the free one's like gmail hotmail etc then you'll find very difficult and all the free tool's i've seen usually give very basic information so you'll do the paid verison, however if its just one search i think it's around $3 or $4 bucks, more then if you want more searches or buy a year subscrition that said someone be able to direct you to a GOOD free email lookup