Lotus Notes had a view entitled "All Documents" which would show you all messages in your mailbox - Inbox, Sent Items, and messages filed in folders.
The Outlook 2013 Windows client does not have this ability out-of-the-box, however you can create a search folder that provides similar functionality.
To create an "All Documents" search folder, perform the following steps:
1. In Outlook for Windows, click on the Folder tab in the ribbon.
2. Click Create New Search Folder
3. Scroll down to the "Custom" heading, and select Create a custom search folder and click the Choose button
4. In the "Custom Search Folder" dialog box, enter the name as All Documents and click OK. There is no need to enter in any other criteria, as you want to see all documents.
5. Click OK to exit the "Custom Search folder" dialog, and click OK again to leave the search folders dialog.
6. Now at the navigation pane on the left hand side of your Outlook client, where your inbox, sent items and folders are, you should see a new folder under your account called "Search Folders" and your "All Documents" search folder will be inside. Click on this folder to see all items stored in your mailbox regardless of their parent folder.