Sent email with iCal to outlook with valarm remind

I am in a situation where I want to send email with iCal attachment to Outlook Calendar and I want to set reminder to 120 minutes before start event.

I send RAW message with iCal(see below). If recipient opens the message, event is automatically added to outlook calendar, but reminder is set to 15 minutes(default in outlook), even if I set different value in VALARM.

If I use ics file with iCal to import to Outlook Calendar then reminder is set to my value.

I would really appreciate help on this. How to set reminder for event?

    $from_name = "<FROM_NAME>";
    $from_address = "<FROM_ADDRESS>";
    $subject = "Meeting Booking";
    $meeting_description = "Here is a brief description of my meeting\n\n";
    $meeting_location = "My Office";
    $domain = 'domain.com';

    $to_name = "<TO_NAME>";
    $to_address = "<TO_ADDRESS>";
    $meeting_date = "2015-10-21 15:40:00";
    $meeting_duration = 3600;

    $meeting_stamp = STRTOTIME($meeting_date . " UTC");
    $dtstart= GMDATE("Ymd\THis\Z",$meeting_stamp);
    $dtend= GMDATE("Ymd\THis\Z",$meeting_stamp+$meeting_duration);

    $mime_boundary = "----Meeting Booking----".MD5(TIME());

    //Create ICAL Content
    $ical = 'BEGIN:VCALENDAR' . "\r\n" .
        'PRODID:-//Patient Portal//MyEyeDr.//EN' . "\r\n" .
        'VERSION:2.0' . "\r\n" .
        'METHOD:REQUEST' . "\r\n" .
        'BEGIN:VEVENT' . "\r\n" .
        'ORGANIZER;CN="'.$from_name.'":MAILTO:'.$from_address. "\r\n" .
        'ATTENDEE;CN="'.$to_name.'";ROLE=REQ-PARTICIPANT;RSVP=TRUE:MAILTO:'.$to_address. "\r\n" .
        'LAST-MODIFIED:' . date("Ymd\TGis") . "\r\n" .
        'UID:'.date("Ymd\TGis", strtotime($meeting_date)).rand()."@".$domain."\r\n" .
        'DTSTAMP:'.date("Ymd\TGis"). "\r\n" .
        'DTSTART;TZID="America/New_York":'.$dtstart. "\r\n" .
        'DTEND;TZID="EAmerica/New_York":'.$dtend. "\r\n" .
        'SEQUENCE:1'. "\r\n" .
        'SUMMARY:' . $subject . "\r\n" .
        'LOCATION:' . $meeting_location . "\r\n" .
        'CLASS:PUBLIC'. "\r\n" .
        'PRIORITY:5'. "\r\n" .
        'BEGIN:VALARM'. "\r\n" .
        'ACTION:Display'. "\r\n" .
        'DESCRIPTION:'.$meeting_description. "\r\n" .
        'SUMMARY:Event Alarm'. "\r\n" .
        'TRIGGER:-PT120M'. "\r\n" .
        'END:VALARM'. "\r\n" .
        'END:VEVENT'. "\r\n" .
        'END:VCALENDAR'. "\r\n";

    $message= "To: ".$to_address."\n";
    $message.= "From: ".$from_address."\n";
    $message.= "Subject: Example SES mail (raw)\n";
    $message.= "MIME-Version: 1.0\n";
    $message .= "Content-Type: multipart/alternative; boundary=\"$mime_boundary\"\n";
    $message .= "Content-class: urn:content-classes:calendarmessage\n";
    $message.= "\n\n";
    $message .= "--$mime_boundary\r\n";
    $message .= "Content-Type: text/html; charset=UTF-8\n";
    $message .= "Content-Transfer-Encoding: 8bit\n\n";
    $message .= "<html>\n";
    $message .= "<body>\n";
    $message .= '<p>Dear ...,</p>';
    $message .= '<p>This is an email message.</p>';
    $message .= "</body>\n";
    $message .= "</html>\n";
    $message .= "--$mime_boundary\r\n";
    $message .= 'Content-Type: text/calendar;name="meeting.ics";method=REQUEST'."\n";
    $message .= "Content-Transfer-Encoding: 8bit\n\n";
    $message .= "X-Mailer: Microsoft Office Outlook 15.0\r\n";
    $message .= $ical;

回答1:

I think there is nothing wrong with your code. Most calendar clients will ignore any alarm that is sent along with an invitation. When you think about it, this makes sense: if you invite me, I may want to accept or decline, but you should not dictate when I want to be notified.

On the other hand, when importing, you are making those events your own.

回答2:

Change METHOD:REQUEST to METHOD:PUBLISH. Also change your other method code at the bottom from method=REQUEST to method=PUBLISH.