Sending Outlook meeting requests without Outlook?

Question

I just wonder if it is possible to send Meeting Requests to people without having Outlook installed on the Server and using COM Interop (which I want to avoid on a server at

Answer 1

The code below will send a meeting request in such a way that Outlook will render Accept/Decline buttons.

Note that UID must be unique per meeting, I've used a GUID.

Also note you need to replace CREATED, DTSTART, DTEND, DTSTAMP, LAST-MODIFIED. These are UTC date/times.

    var m = new MailMessage();

    m.Subject = "Meeting";

    m.Body = "";

    string iCal = 
@"BEGIN:VCALENDAR
PRODID:-//Microsoft Corporation//Outlook 14.0 MIMEDIR//EN
VERSION:2.0
METHOD:PUBLISH
X-MS-OLK-FORCEINSPECTOROPEN:TRUE
BEGIN:VEVENT
CLASS:PUBLIC
CREATED:20140423T045933Z
DESCRIPTION:desc
DTEND:20140430T080000Z
DTSTAMP:20140423T045933Z
DTSTART:20140430T060000Z
LAST-MODIFIED:20140423T045933Z
LOCATION:location...
PRIORITY:5
SEQUENCE:0
SUMMARY;LANGUAGE=en-us:Summary...
TRANSP:OPAQUE
UID:D8BFD357-88A7-455C-86BC-C2CECA9AC5C6
X-MICROSOFT-CDO-BUSYSTATUS:BUSY
X-MICROSOFT-CDO-IMPORTANCE:1
X-MICROSOFT-DISALLOW-COUNTER:FALSE
X-MS-OLK-AUTOFILLLOCATION:FALSE
X-MS-OLK-CONFTYPE:0
BEGIN:VALARM
TRIGGER:-PT60M
ACTION:DISPLAY
DESCRIPTION:Reminder
END:VALARM
END:VEVENT
END:VCALENDAR";

    using (var iCalView = AlternateView.CreateAlternateViewFromString(iCal, new System.Net.Mime.ContentType("text/calendar")))
    {
        m.AlternateViews.Add(iCalView);

        var c = new SmtpClient();

        // Send message
        c.Send(m);
    }

This assumes you have a local SMTP server configured in your config file: