$header = "MIME-Version: 1.0\r\n";
$header .= "Content-type: text/html; charset=utf-8\r\n";
$header .= "From: {$name} <{$sender}>\r\n";
// to subject message header
$result = mail("тут_моя_почта", "Сообщение с сайта ".$your_site_name, nl2br($message), $header);