How can i search for a friend email?

I'm looking for a website that I could search for an email of long time important friend that I lost touch with. But all the websites I find they charge. And they don't give the information unless u pay.. can anyone help me?|||Use their facebook information page. If they don't have a Facebook or other social account network, it's costly to use any E-mail finding websites, and it may also be illegal.|||no authentic website gives you such option, authentic and private information can't be share with anyone, you can't find such options on internet