No, you can't send an email to anyone without knowing their email address. You can try some of the searches that are out there to locate the person or maybe they use the Internet and have contact information on yahoo, myspace, facebook or some other type of site that will get info to you. I have not heard of the site that Fahad talks of but even they will send you the email address so that you know it (or have it). Heck, depending on how long ago you knew this person, you might even try going back to a school they graduated from to see if they have some contact information they can share with you.
