To subscribe to your Sane folders:
Go to the Tools menu on the application toolbar and choose IMAP Folders. Select the folder you would like to subscribe to and click Subscribe.
Press the OK button and you will notice that the new folders are now available.
If you still don't see @SaneLater, your Outlook profile might be corrupted.
Please follow these instructions from Microsoft to fix it: http://support.microsoft.com/kb/829918
If you still don't see @SaneLater or your other folders, you're probably using POP to view your mail. You need to switch to IMAP in order to use SaneBox. Luckily, here are the instructions on how to do that: http://www.pop2imap.com