Here are the steps you need to take to get all your folders to show up.
1. Login at the Webmail interface with your email address and password.
You'll see your current folders on the main screen on the left column.
2. Click on the "Settings" link at the top right hand corner of the screen.
3. On the left hand side column, click on the "Folders" link.
4. To the right of that column you'll see all the folders you have on your account.
Select all the folders you want to be shown when you log into the webmail interface.
5. Once selected, click on the "Mail" icon at the top right hand corner.
6. Now you'll see all the folders you've selected on your main screen.