Sample Outlook Add-in code to enumerate items

ThisAddIn.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Xml.Linq;
using Outlook = Microsoft.Office.Interop.Outlook;
using Office = Microsoft.Office.Core;

namespace ConnectSampleAddin
{
    public partial class ThisAddIn
    {        

        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            EnumAllFoldersInStore();
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        private void EnumAllFoldersInStore()
        {
            Outlook.Folder rootFolder = this.Application.Session.DefaultStore.GetRootFolder() as Outlook.Folder;
            EnumFolder(rootFolder);
        }

        private void EnumFolder(Outlook.Folder folder)
        {
            Outlook.Items allFolderItems = folder.Items;
            if (allFolderItems.Count > 0) // If we have any items in this folder
            {
                for (int i = 1; i < allFolderItems.Count; i++) // Index starts at 1 for Items collection
                {
                    object folderItem = allFolderItems[i];

                    // If item is a MailItem, cast it to a MailItem.
                    // You should have similar code for ContactItem, etc. etc.
                    if (folderItem is Outlook.MailItem)
                    {
                        Outlook.MailItem mailItem = folderItem as Outlook.MailItem;

                        // Get PR_MESSAGE_CLASS property
                        object prMsgClass = mailItem.PropertyAccessor.GetProperty("http://schemas.microsoft.com/mapi/proptag/0x001A001E");
                        string msgClass = prMsgClass.ToString();

                        // Determine if the item is an Enterprise Vault item
                        if (msgClass.Contains("IPM.Note.EnterpriseVault.Shortcut"))
                            MessageBox.Show("Found an Enterprise Vault item.");
                        else
                            MessageBox.Show("This is not an Enterprise Vault item.");
                    }
                }
            }


            // Enum child folders of this one
            Outlook.Folders childFolders = folder.Folders;

            if(childFolders.Count > 0)
            {
                foreach (Outlook.Folder childFolder in childFolders)
                    EnumFolder(childFolder);
            }
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }
        
        #endregion
    }
}