Mails via mail() er ulæselig

Når jeg sender mails ud via mail()-funktionen er der nogle mail-servere/klienter der gør mailen ulæselig (eksempelvis Ofir). Har i oplevet det før og hvad i himlens navn kan der være galt. Jeg mener jeg overholder MIME formatet (se koden):


>===== Original Message From mail@mail.dk =====
>ýW§µéb²×Ÿ¢Yþ{½çjzµvË^þ™ZvÇ«þþŠÚž
Iǧþz¢¶â×¥±Šzz¹Þþøý۲֝Š
þ)íz·¬±êÞjj
z©ì
þ¢¶§zŠ’G«…çl¥êì¢v¥þ«þ«þWŠ
¦V±êJJâž×§þ‰êçžÖ¤µëþ}©]þø¥þ7 þ
«j÷zzWŸ¢zY^ýÛŠ
IþêÞýêŠ{^ ë,z· Š|®‹$ŠW^ý÷¬¶+ÚüW¬¶+Ú–Èb–ÉÞ¬Ib¶Ç!j:¶§qéÞ


KODE

    $from or die("sender address missing");
    $to or die("recipient address missing");
    $boundary="Message-Boundary-19990614";

        $mp = popen("/usr/sbin/sendmail -f $from $to", "w");

    $patterns[0] = "/ø/";
    $patterns[1] = "/å/";
    $patterns[2] = "/æ/";
    $patterns[3] = "/ /";
    $patterns[4] = "/Ø/";
    $patterns[5] = "/Å/";
    $patterns[6] = "/Æ/";

    $replacements[6] = "=F8";
    $replacements[5] = "=E5";
    $replacements[4] = "=E6";
    $replacements[3] = "_";
    $replacements[2] = "=D8";
    $replacements[1] = "=C5";
    $replacements[0] = "=C6";


    $subject = preg_replace($patterns, $replacements, $subject);

        fputs($mp, "MIME-Version: 1.0\n");
        fputs($mp, "Content-Type: Multipart/Mixed; boundary=\"$boundary\"\n");
        fputs($mp, "Content-Transfer-Encoding:Base64\n");
        fputs($mp, "From: $from\n");
        fputs($mp, "To: $to\n");
        fputs($mp, "Subject: =?ISO-8859-1?Q?".$subject."?= \n");
    fputs($mp, "--$boundary\n");
    fputs($mp, "Content-Type: text/plain; charset=\"ISO-8859-1\"\n");
//    fputs($mp, "\n");
    fputs($mp, $message1."\n");

    if(sizeOf($filename)>0)
    {
        //$AttmFiles=array("/var/www/xml/documents/".$filename);
        $AttmFiles=$filename;

        if($AttmFiles){
            foreach($AttmFiles as $AttmFile){
                $AttmFile = ereg_replace(' ', '_', $AttmFile);
                $patharray = explode ("/", $AttmFile);
                  $FileName=$patharray[count($patharray)-1];
       
                $fd2=fopen ($AttmFile, "r");
                $FileContent=fread($fd2,filesize($AttmFile));
                fclose ($fd2);
                $FileContent=chunk_split(base64_encode($FileContent));
                fputs($mp, "--$boundary\n");
                    fputs($mp, "Content-Type: application/octet-stream; name=\"$FileName\"\n");
                    fputs($mp, "Content-Transfer-Encoding: base64\n");
                    fputs($mp, "Content-Disposition: attachment; filename=\"$FileName\"\n");
                    //fputs($mp, "\n");
                    fputs($mp, "$FileContent\n");
                    //fputs($mp, "\n"); 
            }
        }
        $message.="\n--".$boundary."--\n";
    }

        fputs($mp, "--$boundary" . "--\n");
        pclose($mp);