$email = explode("@", $email);
$domain = "http://".$email[1];
$email = implode("@", $email);
$handle = @file_get_contents($domain, null, null, 1);
if(!$handle) die ("
    <h1>Error</h1>
    <p style='margin: 0px; padding-left: 10px; padding-bottom: 20px;'>
        Please specify a valid email address (invalid domain).
    </p>
".$redir);