I have read the forums and no one seems to have an answer for this beyond checking settings.  I have tried several things posted including turning smart filter on and off.  I have no other virus protection than Microsoft essentials and I still have an always empty junk folder.  I have removed any rules, and then re-instated the one I had when things worked.  I have looked at the blocked senders list, and there is hardly anything there.  Seems to have happened after the conversion from mail to outlook.....