Валидация мыла

$email = $_POST['email']; if(preg_match("~([a-zA-Z0-9!#$%&'*+-/=?^_`{|}~])@([a-zA-Z0-9-]).([a-zA-Z0-9]{2,4})~",$email)) { echo 'This is a valid email.'; } else{ echo 'This is an invalid email.'; }