You can adjust the junk e-mail settings within outlook, to tell it who and who is not allowed to send e-mails to your inbox.  In Microsoft Outlook, click "Actions" --> "Junk E-mail" --> "Junk E-mail Options"

From this window, you can adjust the level of protection your computer will use when filtering incoming messages.  Checking the "Permanently Delete Selected Junk E-mail..." box will send incoming messages which Outlook has determined to be "Junk" straight to the Deleted Items folder without making a stop in the Junk Mail folder.  This can save you lots of folder space, however be sure to then check your Deleted Items folder every once in a while, as this folder only retains messages which were deleted up to 2 weeks earlier. 

You can also add safe and blocked senders to their respective lists in this screen by clicking the tabs.