<?php

function validate_email ($email) {
  $regex='/^[\w!#$%&\'*+\/=?^`{|}~.-]+@(?:[a-z\d][a-z\d-]*(?:\.[a-z\d][a-z\d-]*)?)+\.(?:[a-z]+)$/iD';
  
  if (preg_match($regex, $email, $m)) { return $m[0]; }
  return false;
}

var_dump(validate_email('[email protected]'));

?>