title: Outlook Addin appointmentitem PropertyChange event firing too much
body: <p>I'm creating an Outlook addin that needs to trigger when the attendees of a meeting are changed.
  The problem I'm encountering is that the PropertyChange event of an Appointment item is firing way too much and because of that I can't get the exact amount of attendees.</p>
  
  <p>Here is some of the code I'm using:</p>
  
  <pre><code>private Outlook.AppointmentItem appointmentItem;
  private void Inspectors_NewInspector(Outlook.Inspector inspector)
      {
          var item = inspector.CurrentItem as Outlook.AppointmentItem;
          if (item != null)
          {
              appointmentItem = item;
              temp = inspector;
              visible = false;
              appointmentItem.PropertyChange += AppOnPropertyChange;
          }
      }
  
  private void AppOnPropertyChange(string name)
      {
  
          if (name.Equals("RequiredAttendees"))
          {
              var test = appointmentItem.Recipients.Count;
          }
      }
  </code></pre>
  
  <p>The event is triggered way too many times, and thus "test" will get values between 1 (the sender is always an attendee) and the number of attendees. 
  Also if you have lets say 3 attendees and you remove one, "test" will be 4 - 3 - 2 - 1.</p>
  
  <p>Is there a way to figure out the exact number of attendees in an AppointmentItem?</p>
  
  <p>Any help would be much appreciated.</p>