title: C# Outlook add-in get selected emails
body: <p>I want to get all selected emails in my Outlook 2010 add-in. I found this <a href="http://msdn.microsoft.com/en-us/library/ms268994%28v=vs.100%29.aspx" rel="noreferrer">MSDN tutorial</a>, but I am a beginner at C#, and I don't quite understand this line of code: <code>Object selObject = this.Application.ActiveExplorer().Selection[3];</code></p>
  
  <p>I believe <code>Selection[]</code> is something like overridden operator, indexer in C#. But, is there any way to see implementation of it? If I go through the code, I only see interfaces but not implementations. So I don't know the structure of the Selection object. What is really behind the <code>operator []</code>.</p>
  
  <p>Also, why do the selected items begin at index 1 and not 0? </p>