If you see a picture of someone you might know on Facebook, you might want to send him an email. But you have to know how to get an email address from a Facebook profile so you can communicate privately instead of writing on his wall.
Visit the person's page. If the person has not restricted his page, you will be able to see his wall and profile. You will be able to see the email address on the profile page or you can send him a private message.
Ask the person to be your friend. After the person accepts, you can view his profile to get his email address.
If the person's page is restricted, see if you have a friend in common. In the right-hand corner of the screen, you will see names for people you can follow. If you see this person in this box, it means he is friends with someone you know. You can ask the mutual friend to get the email address from the profile page.
Click on the person's name, and it should show you a list of some of his friends. This is another way to find friends you and that person might have in common so you get the email address.