title: iCal.Net events working fine in Gmail but not for Outlook
body: <p>I am using iCal.Net to send meeting invitations. It's working fine on Gmail and it's showing me event like:</p>
  <p><a href="https://i.stack.imgur.com/4NdXw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4NdXw.png" alt="Google invitation" /></a></p>
  <p>But on Outlook it's not showing me any invite like accept, tentative, and decline options. It's showing me like:</p>
  <p><a href="https://i.stack.imgur.com/TnRl1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TnRl1.png" alt="Outlook invitaiton" /></a></p>
  <p>It should be shown like this:</p>
  <p><a href="https://i.stack.imgur.com/Unk2H.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Unk2H.png" alt="Outlook the way it should look" /></a></p>
  <p>Here is my code:</p>
  <pre><code>async Task&lt;SendResponse&gt; CreateCalendarEventAsync(
          CalendarNotificationModel calendarNotificationModel)
  {
  var attendees = calendarNotificationModel.Attendees.Select(x =&gt; new 
  Ical.Net.DataTypes.Attendee()
  {
      CommonName = x.AttendeeName,
      ParticipationStatus = &quot;REQ-PARTICIPANT&quot;,
      Rsvp = true,
      Role = &quot;REQ-PARTICIPANT&quot;,
      Value = new Uri($&quot;mailto:{x.AttendeeEmail}&quot;)
  }).ToList();
  
  var e = new CalendarEvent
  {
      Summary = calendarNotificationModel.Name,
      IsAllDay = true,
      
      Organizer = new Organizer()
      {
          CommonName = &quot;HRMatrix&quot;,
          Value = new Uri(&quot;mailto:xyz@zxy.com&quot;)
      },
      Attendees = attendees,
      Status = &quot;Confirmed&quot;,
      Sequence = 0,
      Start = new CalDateTime(calendarNotificationModel.StartDateTime),
      End = new CalDateTime(calendarNotificationModel.EndDateTime),
      Transparency = TransparencyType.Opaque,
      Location = calendarNotificationModel.Location,
      Description = calendarNotificationModel.Description
  };
  
  var calendar = new Calendar();
  calendar.AddProperty(&quot;X-MS-OLK-FORCEINSPECTOROPEN&quot;, &quot;TRUE&quot;);
  calendar.AddProperty(&quot;METHOD&quot;, &quot;REQUEST&quot;);
  
  calendar.Events.Add(e);
  
  var serializer = new CalendarSerializer();
  var serializedCalendar = serializer.SerializeToString(calendar);
  
  var bytesCalendar = Encoding.ASCII.GetBytes(serializedCalendar);
  MemoryStream ms = new MemoryStream(bytesCalendar);
  using (ms)
  {
      ms.Position = 0;
  
  
      SmtpClient smtp = new SmtpClient
      {
          //The address of the SMTP server (I'll take mailbox 126 as an example, which can 
  be set according to the specific mailbox you use)
          Host = &quot;smtp.gmail.com&quot;,
          EnableSsl = true,
          Port = 587,
          DeliveryMethod = SmtpDeliveryMethod.Network,
          //Enter the user name and password of your sending SMTP server here
          Credentials  = new NetworkCredential(&quot;xyz@xyz&quot;, &quot;sdfsdfsdfsdf&quot;)
      };
      //Set default sending information
      Email.DefaultSender = new SmtpSender(smtp);
      var email = Email
          //Sender
          .From(&quot;xyz@xyz&quot;)
          //Addressee
          .To(&quot;denis@org.com&quot;)
          //Message title
          .Subject(&quot;Interview&quot;)
          //Email content
          .Body(&quot;You are invited.&quot;);
      //Determine whether the transmission is successful according to the transmission 
   result
  
      var attachment = new FluentEmail.Core.Models.Attachment
      {
          Data = ms,
          ContentType = &quot;text/calendar&quot;,
          Filename = &quot;invite.ics&quot;,
      };
      email.Attach(attachment);
  
      var result = email.Send();
      //Or send it asynchronously
      //await email.SendAsync();
  
      return result;
  }
  </code></pre>
  <p>}</p>
  <p>Here is my .ics file:</p>
  <pre><code> BEGIN:VCALENDAR
   METHOD:Request
   PRODID:-//github.com/rianjs/ical.net//NONSGML ical.net 4.0//EN
   VERSION:2.0
   X-MS-OLK-FORCEINSPECTOROPEN:TRUE
   BEGIN:VEVENT
   ATTENDEE;CN=XYZ;PARTSTAT=REQ-PARTICIPANT;RSVP=TRUE;ROLE=REQ-PARTICIPA
    NT:mailto:XYZ@hotmail.com
   DESCRIPTION:You are invited to give an interview
   DTEND:20220208T091006
   DTSTAMP:20220207T181006Z
   DTSTART:20220208T041006
   LOCATION:Pakistan
   ORGANIZER;CN=HRMatrix:mailto:xyz@gmail.com
   SEQUENCE:0
   STATUS:Confirmed
   SUMMARY:XYZ
   TRANSP:OPAQUE
   UID:b2ddc1ef-a2e4-4b0e-afa0-27d9689fbsdf
   END:VEVENT
   END:VCALENDAR
  </code></pre>
  <p>PS: if I send the above .ics file from Gmail client it works but it does not work from my SMTP client.</p>