Outlook 2013: Mailbox Cleanup Feature
Outlook 2013 contains a "Mailbox Cleanup" tool that lets you quickly empty your Deleted Items folder, as well as check how much space is being used by each of your other folders. This guide will show how to use this tool.
Open Outlook and left-click the File tab at the far left-hand side of the ribbon at the top of the window.
In the Account Information pane, left-click "Cleanup Tools."
In the menu that appears, left-click "Mailbox Cleanup."
In the Mailbox Cleanup window you can left-click "View Mailbox Size" to see how much space is being taken up by the items in each of your folders. Left-clicking "View Deleted Items Size" lets you see specifically how much space is in the Deleted Items folder. Left-clicking "Empty" allows you to permanently delete all items from your Deleted Items folder. If you decide to left-click "View Mailbox Size," proceed to Step 5.
The window shown above contains a list of each folder and the amount of space being taken up by items in that folder. This should help you decide which folders need to be cleaned out, and which ones do not need to be cleaned out.
Outlook 2013 is the latest full-featured emailing, calendar, and contact management software from the Microsoft Office suite.