title: Outlook interop opening too many items causes error
body: <p>My goal is to open shared calendars for analysis and database tracing.</p>
  
  <p>The point is I manage to open the items but after a few hundreds, I get an exception.
  It explains that the administrator (security reasons) limited the amount of simultenaous openned items.</p>
  
  <p>I can understand this so I've tried to close each item after reading it. But I still get the error. The problem appears when I'm reading user properties.</p>
  
  <p>Here is a sample of my program:</p>
  
  <pre><code>Recipient recipient = mapiNamespace.CreateRecipient("John Doe");
  if (recipient.Resolve())
  {
      CalendarFolder = mapiNamespace.GetSharedDefaultFolder(recipient, OlDefaultFolders.olFolderCalendar);
      outlookCalendarItems = CalendarFolder.Items;
      outlookCalendarItems.IncludeRecurrences = false;
  }
  else
  {
      Console.Write("Failed to open Calendar");
      return;
  }
  
  foreach (Microsoft.Office.Interop.Outlook.AppointmentItem item in outlookCalendarItems)
  {
      Console.WriteLine(item.Subject + " -&gt; " + item.Start.ToLongDateString());   //=&gt; Ok, no problem
      UserProperty up = item.UserProperties.Find("Test");                   //=&gt; Problem if too many items
      if( up!= null )
      {
          Console.Write("UserProperty Value: " + up.Value);
      }
  
      ((Microsoft.Office.Interop.Outlook._AppointmentItem)item).Close(OlInspectorClose.olDiscard);   //=&gt; Problem if too many items
      Console.WriteLine();
  
  }
  
  Console.ReadKey();
  </code></pre>
  
  <p>Any idea on how to properly close the items?</p>