You could try contacting Yahoo about the email, I'm not sure how well that would work, but you've got tons to work with on the domain name.<p>You're you, he's not. Dispute the domain, how it's your name and your address: <a href="http://wdprs.internic.net/" rel="nofollow">http://wdprs.internic.net/</a><p>Additionally check out <a href="http://www.icann.org/en/udrp/" rel="nofollow">http://www.icann.org/en/udrp/</a> if you want to go further.