I have some code, referenced below which creates a MailMessage which is
really a meeting request because when it shows up in my Outlook I can
accept/decline like with any other meeting request. This is great. However,
now I am trying to add attachments to the MailMessage using the code
commented below, when I do this, it successfully adds the attachment however
when the email is received in Outlook it is no longer a meeting request I
can accept/decline, instead it's just an email with the meeting information
inside of it and the attachment attached. How do I programmatically attach
the attachment while at the same time keeping the meeting request
functionality? Or if this is the incorrect newsgroup, please point me to the
correct one?
Thanks

public static MailMessage CreateMeetingRequest(DateTime start, DateTime end,
string subject, string summary, string location, string organizerName,
string organizerEmail, MailAddressCollection attendeeList, Attachment
attachedFile, string fileName)
{
MailMessage msg = new MailMessage();

//add the attachment to the appointment, when added it shows up
as a regular email and not the expected appointment like I thought it would
if (attachedFile != null)
{
msg.Attachments.Add(attachedFile);
}

// Set up the different mime types contained in the message
System.Net.Mime.ContentType textType = new
System.Net.Mime.ContentType("text/plain");
System.Net.Mime.ContentType HTMLType = new
System.Net.Mime.ContentType("text/html");
System.Net.Mime.ContentType calendarType = new
System.Net.Mime.ContentType("text/calendar");

// Add parameters to the calendar header
calendarType.Parameters.Add("method", "REQUEST");
calendarType.Parameters.Add("name", "meeting.ics");

// create the Body in text format
string bodyText = "Type:Single Meeting\r\nOrganizer:
{0}\r\nStart Time:{1}\r\nEnd Time:{2}\r\nTime Zone:{3}\r\nLocation:
{4}\r\n\r\n*~*~*~*~*~*~*~*~*~*\r\n\r\n{5}";
bodyText = string.Format(bodyText, organizerName,
start.ToLongDateString() + " " + start.ToLongTimeString(),
end.ToLongDateString() + " " + end.ToLongTimeString(),
System.TimeZone.CurrentTimeZone.StandardName, location, summary);
AlternateView textView =
AlternateView.CreateAlternateViewFromString(bodyTe xt, textType);
LinkedResource lr = new LinkedResource(fileName);
textView.LinkedResources.Add(lr);
msg.AlternateViews.Add(textView);

//create the Body in HTML format
string bodyHTML = "!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML
3.2//EN\"\r\nHTML\r\nHEAD\r\nMETA HTTP-EQUIV=\"Content-Type\"
CONTENT=\"text/html; charset=utf-8\"\r\nMETA NAME=\"Generator\"
CONTENT=\"MS Exchange Server version
6.5.7652.24\"\r\nTITLE{0}/TITLE\r\n/HEAD\r\nBODY\r\n!-- Converted
from text/plain format --\r\nPFONT SIZE=2Type:Single
MeetingBR\r\nOrganizer:{1}BR\r\nStart Time:{2}BR\r\nEnd
Time:{3}BR\r\nTime
Zone:{4}BR\r\nLocation:{5}BR\r\nBR\r\n*~*~*~ *~*~*~*~*~*~*BR\r\nBR\r\n{6}BR\r\n/FONT\r\n/P\r\n\r\n/BODY\r\n/HTML";
bodyHTML = string.Format(bodyHTML, summary, organizerName,
start.ToLongDateString() + " " + start.ToLongTimeString(),
end.ToLongDateString() + " " + end.ToLongTimeString(),
System.TimeZone.CurrentTimeZone.StandardName, location, summary);
AlternateView HTMLView =
AlternateView.CreateAlternateViewFromString(bodyHT ML, HTMLType);
HTMLView.LinkedResources.Add(lr);
msg.AlternateViews.Add(HTMLView);

//create the Body in VCALENDAR format
string calDateFormat = "yyyyMMddTHHmmssZ";
string bodyCalendar =
"BEGIN:VCALENDAR\r\nMETHOD:REQUEST\r\nPRODID:Micro soft CDO for Microsoft
Exchange\r\nVERSION:2.0\r\nBEGIN:VTIMEZONE\r\nTZID GMT-06.00) Central Time
(US &
Canada)\r\nX-MICROSOFT-CDO-TZID:11\r\nBEGIN:STANDARD\r\nDTSTART:16010101T0200 00\r\nTZOFFSETFROM:-0500\r\nTZOFFSETTO:-0600\r\nRRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMON TH=11;BYDAY=1SU\r\nEND:STANDARD\r\nBEGINAYLIGHT\ r\nDTSTART:16010101T020000\r\nTZOFFSETFROM:-0600\r\nTZOFFSETTO:-0500\r\nRRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMON TH=3;BYDAY=2SU\r\nENDAYLIGHT\r\nEND:VTIMEZONE\r\ nBEGIN:VEVENT\r\nDTSTAMP:{8}\r\nDTSTART:{0}\r\nSUM MARY:{7}\r\nUID:{5}\r\nATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN=\"{9}\":MAILTO:{9}\r\nACTION;R SVP=TRUE;CN=\"{4}\":MAILTO:{4}\r\nORGANIZER;CN=\"{ 3}\":mailto:{4}\r\nLOCATION:{2}\r\nDTEND:{1}\r\nDE SCRIPTION:{7}\\N\r\nSEQUENCE:1\r\nPRIORITY:5\r\nCL ASS:\r\nCREATED:{8}\r\nLAST-MODIFIED:{8}\r\nSTATUS:CONFIRMED\r\nTRANSP:OPAQUE\ r\nX-MICROSOFT-CDO-BUSYSTATUS:BUSY\r\nX-MICROSOFT-CDO-INSTTYPE:0\r\nX-MICROSOFT-CDO-INTENDEDSTATUS:BUSY\r\nX-MICROSOFT-CDO-ALLDAYEVENT:FALSE\r\nX-MICROSOFT-CDO-IMPORTANCE:1\r\nX-MICROSOFT-CDO-OWNERAPPTID:-1\r\nX-MICROSOFT-CDO-ATTENDEE-CRITICAL-CHANGE:{8}\r\nX-MICROSOFT-CDO-OWNER-CRITICAL-CHANGE:{8}\r\nBEGIN:VALARM\r\nACTIONISPLAY\r\nDE SCRIPTION:REMINDER\r\nTRIGGER;RELATED=START:-PT00H15M00S\r\nEND:VALARM\r\nEND:VEVENT\r\nEND:VCA LENDAR\r\n";
bodyCalendar = string.Format(bodyCalendar,
start.ToUniversalTime().ToString(calDateFormat),
end.ToUniversalTime().ToString(calDateFormat), location, organizerName,
organizerEmail, Guid.NewGuid().ToString("B"), summary, subject,
DateTime.Now.ToUniversalTime().ToString(calDateFor mat), attendeeList);
AlternateView calendarView =
AlternateView.CreateAlternateViewFromString(bodyCa lendar, calendarType);
calendarView.TransferEncoding =
System.Net.Mime.TransferEncoding.SevenBit;
calendarView.LinkedResources.Add(lr);
msg.AlternateViews.Add(calendarView);

// Adress the message
msg.From = new MailAddress(organizerEmail);
foreach (MailAddress attendee in attendeeList)
{
msg.To.Add(attendee);
}

msg.Subject = subject;
return msg;
}