Send an ics appointment email in Outlook

Question

I want to send an appointment \ Meeting email (ICS) to an Outlook client. When a user receives an email, he must accept the meeting invitation and will automatically meet on the calendar, and the email will be automatically deleted.

I am using this code:

public void Sendmail_With_IcsAttachment()
{

    MailMessage msg = new MailMessage();
    //Now we have to set the value to Mail message properties

    //Note Please change it to correct mail-id to use this in your application
    msg.From = new MailAddress("[e-mail]", "ABC");
    msg.To.Add(new MailAddress("[e-mail]", "BCD"));
    msg.CC.Add(new MailAddress("[e-mail]", "DEF"));// it is optional, only if required
    msg.Subject = "Send mail with ICS file as an Attachment";
    msg.Body = "Please Attend the meeting with this schedule";

    // Now Contruct the ICS file using string builder
    StringBuilder str = new StringBuilder();
    str.AppendLine("BEGIN:VCALENDAR");
    str.AppendLine("PRODID:-//Schedule a Meeting");
    str.AppendLine("VERSION:2.0");
    str.AppendLine("METHOD:REQUEST");
    str.AppendLine("BEGIN:VEVENT");
    str.AppendLine(string.Format("DTSTART:{0:yyyyMMddTHHmmssZ}", DateTime.Now.AddMinutes(+330)));
    str.AppendLine(string.Format("DTSTAMP:{0:yyyyMMddTHHmmssZ}", DateTime.UtcNow));
    str.AppendLine(string.Format("DTEND:{0:yyyyMMddTHHmmssZ}", DateTime.Now.AddMinutes(+660)));
    str.AppendLine("LOCATION: " + this.Location);
    str.AppendLine(string.Format("UID:{0}", Guid.NewGuid()));
    str.AppendLine(string.Format("DESCRIPTION:{0}", msg.Body));
    str.AppendLine(string.Format("X-ALT-DESC;FMTTYPE=text/html:{0}", msg.Body));
    str.AppendLine(string.Format("SUMMARY:{0}", msg.Subject));
    str.AppendLine(string.Format("ORGANIZER:MAILTO:{0}", msg.From.Address));

    str.AppendLine(string.Format("ATTENDEE;CN=\"{0}\";RSVP=TRUE:mailto:{1}", msg.To[0].DisplayName, msg.To[0].Address));

    str.AppendLine("BEGIN:VALARM");
    str.AppendLine("TRIGGER:-PT15M");
    str.AppendLine("ACTION:DISPLAY");
    str.AppendLine("DESCRIPTION:Reminder");
    str.AppendLine("END:VALARM");
    str.AppendLine("END:VEVENT");
    str.AppendLine("END:VCALENDAR");

    //Now sending a mail with attachment ICS file.                     
    System.Net.Mail.SmtpClient smtpclient = new System.Net.Mail.SmtpClient();
    smtpclient.Host = "localhost"; //-------this has to given the Mailserver IP

    smtpclient.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;

    System.Net.Mime.ContentType contype = new System.Net.Mime.ContentType("text/calendar");
    contype.Parameters.Add("method", "REQUEST"); 
    contype.Parameters.Add("name", "Meeting.ics");
    AlternateView avCal = AlternateView.CreateAlternateViewFromString(str.ToString(), contype);
    msg.AlternateViews.Add(avCal);
    smtpclient.Send(msg); 
}

The mail was sent correctly, but in Outlook (I test it using Outlook 2010) it shows the body, location, data, and the calendar, but above the calendar by mail I see "Unable to find the appointment on the calendar", and the "Accept", "Reject" buttons "disconnected!

I tried other solutions and found on the Internet for ex. DDAY.Ical, but I did not find any example to use it.

Answer 1

:

eMail

Content-class: urn:content-classes:calendarmessage

,

msg.Headers.Add("Content-class", "urn:content-classes:calendarmessage");

Answer 2

, msg.From msg.To

msg.From = new MailAddress("[e-mail]", "ABC");
msg.To.Add(new MailAddress("[e-mail]", "BCD"));

, , , .