Facebook Graph API, how to get users email?

The only way to get the users e-mail address is to request extended permissions on the email field. The user must allow you to see this and you cannot get the e-mail addresses of the user's friends.

http://developers.facebook.com/docs/authentication/permissions

You can do this if you are using Facebook connect by passing scope=email in the get string of your call to the Auth Dialog.

I'd recommend using an SDK instead of file_get_contents as it makes it far easier to perform the Oauth authentication.

// Facebook SDK v5 for PHP// https://developers.facebook.com/docs/php/gettingstarted/5.0.0$fb = new Facebook\Facebook([  'app_id' => '{app-id}',  'app_secret' => '{app-secret}',  'default_graph_version' => 'v2.4',]);$fb->setDefaultAccessToken($_SESSION['facebook_access_token']);$response = $fb->get('/me?locale=en_US&fields=name,email');$userNode = $response->getGraphUser();var_dump(    $userNode->getField('email'), $userNode['email']);

Open base_facebook.php Add Access_token at function getLoginUrl()

array_merge(array(                  'access_token' => $this->getAccessToken(),                  'client_id' => $this->getAppId(),                  'redirect_uri' => $currentUrl, // possibly overwritten                  'state' => $this->state),             $params);

and Use scope for Email Permission

if ($user) {   echo $logoutUrl = $facebook->getLogoutUrl();} else {   echo $loginUrl = $facebook->getLoginUrl(array('scope' => 'email,read_stream'));}