Outlook’s Navigation Pane, by default, shows the number of unread items in each Mail Folder. You can change each folder to instead show the total number of items in that mail folder. This is a great way to get a feel of how much email you are actually holding on to. It also is quite useful for monitoring how many messages are in your Deleted Items and Sent Items folders.
1. Go to the Mail Folders in the Navigation Pane.
2. Right-click on a folder, for example Inbox or Deleted Items.
3. Select Properties.
4. On the General tab, beneath the Description memo box, select Show total number of items.
5. Click OK.
Repeat these steps for each mail folder that is to display the total number of items within it.
