How to Find Friends via Their Email Address on Facebook
Facebook allows you reconnect with friends you have lost contact with by using their email addresses to find them. The website has a robust search engine that allows you to find people using many different search criteria, such as a person's email address. The engine searches through Facebook accounts until it finds an account that lists your friend's email address as part of its contact folder. Additionally, you can also use the Friend Finder utility to perform a search for your friends on Facebook using their email addresses.
Launch a Web browser and then go to the Facebook Sign In page.
Sign in to Facebook and then enter the email address of the friend you want to find into the search box. The search box is located at the top of the window and to the right of the Facebook logo.
Click the "Search" icon and then click the "Add as Friend" button to the right of your friend's name in the search results page.
Sign in to your Facebook account and then click "Home" on the upper-right corner of the window.
Click "Friends" in the far-left column under your profile image.
Scroll down the page to locate the "Add Personal Contacts as Friends" section.
Click the service that contains the email addresses of friends you want to find and then enter your email address in the "Your Email" box. For example, to find friends using the email addresses in your Yahoo! account, click "Yahoo!" and then enter your Yahoo! email address in the "Your Email" box.
Enter your password in the pop-up window for your account and then click "Agree." The list of friends from your contacts who also have Facebook accounts is displayed.
Click the check box next to each friend you want to add and then click "Add as Friends."