How to verify email address and MX records with javascript_javascript skills

The example in this article describes the method of verifying email addresses and MX records using JavaScript. Share it with everyone for your reference. The details are as follows:

// Tests for a valid email address and optionally tests for valid MX records, too.
function is_valid_email($email, $test_mx = false)
{
  if(eregi("^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$", $email))
    if($test_mx)
    {
      list($username, $domain) = split("@", $email);
      return getmxrr($domain, $mxrecords);
    }
    else
      return true;
  else
    return false;
}

I hope this article will be helpful to everyone’s JavaScript programming design.