php mail spam sorunu

$ustk = "From: Gönderen<".$kimden.">\n"; 
$ustk .= "Reply-To: $kimden <".$kimden.">\n";
$ustk .= "Return-Path: $kimden <".$kimden.">\n";  
$ustk .= "Delivered-to:  Gönderen<".$kimden.">\n";
$ustk .= "Date: ".date(r)."\n";
$ustk .= "Content-Type: text/html; charset=UTF-8\n";   
$ustk .= "MIME-Version: 1.0\n";
$ustk .= "Importance: Normal\n";
$ustk .= "X-Sender: $kimden <".$kimden.">\n";   
$ustk .= "X-Priority: 3\n";   
$ustk .= "X-MSMail-Priority: Normal\n";
$ustk .= "X-Mailer: Microsoft Office Outlook, Build 11.0.5510\n";
//$ustk .= "Disposition-Notification-To: $g_isim <".$g_mail.">\n";
$ustk .= "X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869\n"; 
$ustk .= "Message-ID: <".time()."-".$kimden.">";