PHP VCALENDAR not working in MAC Outlook

Question

Vcalendar works well in Windows Outlook but not working in MAC Outlook. It shows below message when i receive appointment by email:

charset="UTF-8"
Content-Transfer-Encoding: 7bit

BEGIN:VCALENDAR
VERSION:2.0
METHOD:REQUEST
BEGIN:VEVENT
UID:UID:20120605T112338-532614004-testing
DTSTAMP:20120605T112338
DTSTART:20120605T112338
SUMMARY: Appointment testing
DESCRIPTION: Test appointment
END:VEVENT
END:VCALENDAR

Here is the code i am using for appointment creation:

        $myUID="UID:".date('Ymd').'T'.date('His')."-".rand()."-test".$eol; // required by Outlok
        $message="BEGIN:VCALENDAR".$eol;
        $message.="VERSION:2.0".$eol;
        //$message.="PRODID:-//Foobar Corporation//NONSGML Foobar//EN\n";
        $message.="METHOD:REQUEST".$eol; // requied by Outlook
        $message.="BEGIN:VEVENT".$eol;
        $message.="UID:".$myUID; // required by Outlok
        $message.="DTSTAMP:".date('Ymd').'T'.date('His').$eol; // required by Outlook
        $message.="DTSTART:".date('Ymd').'T'.date('His').$eol;
        $message.="SUMMARY: $attachment_subject".$eol;
        $message.="DESCRIPTION: $notes".$eol;
        $message.="END:VEVENT".$eol;
        $message.="END:VCALENDAR".$eol;     
        $headers = "From: $User <$User_Email>".$eol;
        $headers .= "MIME-Version: 1.0".$eol;
        $headers .= "Content-Type: text/calendar; method=REQUEST;".$eol;
        $headers .= 'charset="UTF-8"';
        $headers .= $eol;
        $headers .= "Content-Transfer-Encoding: 7bit";
        mail("$Email", $subject, $message, $headers)

Answer 1

I did some more research on it and modified the code according to MAC Outlook requirements but still it is coming up with the code instead of appointment as an event in the email:

$message="BEGIN:VCALENDAR".$eol;
$message.="VERSION:2.0".$eol;
$message.="PRODID:-//Microsoft Corporation//Entourage Mac 11.0 MIMEDIR//EN\n";
$message.="METHOD:REQUEST".$eol; // requied by Outlook
$message.="BEGIN:VTIMEZONE".$eol;
$message.="TZID:Abu Dhabi, Muscat".$eol;
$message.="X-ENTOURAGE-TZID:23".$eol;
$message.="X-ENTOURAGE-CFTIMEZONE:Asia/Muscat".$eol;
$message.="BEGIN:STANDARD".$eol;
$message.="TZNAME:Standard".$eol; 
$message.="TZOFFSETFROM:+0400".$eol;
$message.="TZOFFSETTO:+0400".$eol; 
$message.="DTSTART:20090101T010000".$eol;
$message.="END:STANDARD".$eol; 
$message.="END:VTIMEZONE".$eol; 
$message.="BEGIN:VEVENT".$eol;
$message.="UID:E153D577-98BB-4EEE-8FC9-B526A7D09DD1";
$message.="X-ENTOURAGE_UUID:E153D577-98BB-4EEE-8FC9-B526A7D09DD5".$eol; 
$message.="DTSTAMP:".date('Ymd').'T'.date('His').$eol; $message.="DTSTART;TZID='Abu Dhabi, Muscat':20120610T010000".$eol;
$message.="DTEND;TZID='Abu Dhabi, Muscat':20120610T013000".$eol; 
$message.="LAST-MODIFIED:20120609T204400Z".$eol;
$message.="SUMMARY: $attachment_subject".$eol;
$message.="DESCRIPTION: $notes".$eol; 
$message.="ORGANIZER:MAILTO:[email protected]".$eol;
$message.="SEQUENCE:0".$eol;
$message.="ATTENDEE;ROLE=REQ-PARTICIPANT;RSVP=TRUE;CN='Test Contact';PARTSTAT=NEEDS-ACTION:MAILTO:[email protected]".$eol;
$message.="X-MICROSOFT-CDO-BUSYSTATUS:BUSY".$eol; 
$message.="X-MICROSOFT-CDO-ALLDAYEVENT:FALSE".$eol;
$message.="X-MICROSOFT-CDO-INSTTYPE:0".$eol; 
$message.="BEGIN:VALARM".$eol;
$message.="ACTION:DISPLAY".$eol;
$message.="DESCRIPTION:REMINDER".$eol; 
$message.="TRIGGER;RELATED=START:-PT00H15M00S".$eol; 
$message.="END:VALARM".$eol;
$message.="END:VEVENT".$eol;
$message.="END:VCALENDAR"; 
$headers = "From: $User <$User_Email>".$eol;
$headers .= "MIME-Version: 1.0".$eol;
$headers .= "Content-Type: text/calendar;method=REQUEST;".$eol;
$headers .= 'charset="UTF-8";name="meeting.ics"';
$headers .= $eol;
$headers .= "Content-Transfer-Encoding: 7bit";