How can you search for someone's email address?

I want to search for my friends e-mail address so I can add him to MSN. I have his phone number and everything... But I haven't spoken to him in 4 years and would like to e-mail him first. Is there any way I can do this? Can I search for his hotmail address at all?|||Use this search engine...|||i dont think so..if u have his hand phone number try starting with an sms, if u dont want to call