- Go to File>Info>Account and Social Network Settings>Account Settings
- Double-click the account on the E-mail Tab
- Under Offline Settings, drag the slider all the way to the right. It should now say All
- Click Next and Finish.
- Close Outlook and open it again.
You should see the progress in the status bar. Outlook may be a little slow while it is updating your mailbox but once the status shows All folders are up to date, you are good to go.