- filter_var: documentation ( source)
<?php
$email1 = "nonsense.something@dottiness"; // not a valid email
$email2 = "dotty@something.whatever"; // valid email
$clean_email1 = filter_var($email1, FILTER_VALIDATE_EMAIL); // $clean_email1 = false
$clean_email2 = filter_var($email2, FILTER_VALIDATE_EMAIL); // $clean_email2 = dotty@something.whatever