Spam not moved to Junk Folder in Outlook 2013

Norton seems to be identifying spam, but only about half of it is being put in the Junk Folder.  I'm consistently getting about half of the spam, identifed with "[Norton Antispam]" at the beginning of the subject line, left in my Inbox folder.  This had been working up properly until I renewed my license a couple of weeks ago, but now I have to go through my Inbox every day and manually delete the spam.