PHP function to validate an email address

validate_email.php

<?php
function check_valid_email($email) {
	$regex = '/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/'; 
	if (preg_match($regex, $email)) {
 		return true;
	} else { 
 		return false;
	} 
}