Marking Junk Mail not working in Outlook (client)

I'm not entirely sure how to describe this but let tell you my situation. 

I am using Norton Security with the client version of Outlook. When I mark an email in my Inbox as Spam, I would expect any new messages coming from that email or domain would get marked and moved to the Junk folder. I'm not seeing that. So I started to add the Domain names to Settings>AntiSpam>Blocked List. But I'm still seeing junk mail from that domain still in my Inbox. 

Can these people create an Alias domain name to get around this Block List? If so, how do I determine the actual domain name so I can block it?

Hope that makes sense, if not ask your questions so I can find a solution. 

Thanks,

Greg