How to get facebook user's email address?

Once the user login via facebook using Social Login how can i get the user’s email address?

I am getting username as shown below but do not know how to pull email address?

foreach ($data->user->identity->accounts as $account) {
                    $user_emailId = $account->username;
                }

I am more interested of getting user’s email instead of facebook email. I do ask user for the permission too.

http://wordpress.org/extend/plugins/oa-social-login/