title: Outlook add-in failed to read attachment path
body: <p>I am trying to obtain the attachment path before a mail is sent from outlook. However when I try so, the result <code>null</code>. Here is my code:</p>
  
  <pre><code>public partial class ThisAddIn
  {
      private void ThisAddIn_Startup(object sender, System.EventArgs e)
      {
          Application.ItemSend += new Outlook.ApplicationEvents_11_ItemSendEventHandler(Application_ItemSend);
      }
  
      void Application_ItemSend(object Item, ref bool Cancel)
      {
  
          Outlook.MailItem mail = Item as Outlook.MailItem;
  
          var atts = mail.Attachments;
  
          foreach (Outlook.Attachment attachment in atts)
          {
              MessageBox.Show(attachment.PathName); // the PathName is null !
          }
      }
  
      private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
      {
  
      }
  }
  </code></pre>
  
  <p>The user creates a new mail and adds attachments which is already on hard-disk. How can I obtain the path information of the chosen files ?</p>