Outlook 2013 stopped downloading email 11-13-13

Yesteday I downloaded email via Outlook 2013 in the morning, and then started noticing that I was getting notifications via the Email App that I had new mail, but Outlook 2013 was not finding it, although it says it is connecting to the server. I routinely use Outlook 2013 in its Classic Shell, and not the Email App in Windows 8.1.

When I sign on to my ISP and check my email on the server, it is all there. When I check the Email App, it is there, but it is not downloading to through Outlook 2013.

Any idea what the problem could b?  It was working properly, and then it wasn't. I have rebooted my computer, and checked my Outlook email settings, nothing looks to be wrong there. I obviously have internet connectivity.  Outlook just looks like it has stopped working as far as the email downloading portion is concerned.

Thanks.

F. Tyler