I don't know if the solution you found works but if in case of it wouldn't you can try the following :

Using the mail filtering wizard you can test the sender's address and send him/her a reply recorded in a text file.

HTH

I think what I want to do is known as blacklisting a sender but I cannot find a way to do that. Can anyone help me? I will settle for mail from this person going to junk but I would rather it went back to them with a message hat it was refused. Can someone enlighten me?

I think I got it done but time will tell. I do think the program should have fewer features so that the ones that remained would be easier to figure out. What I did was create a mail filtering rule to the effect chat when my mail is downloaded addresses on my junk blacklist get deleted. That took some figuring out. Then I figured out that the two default distribution lists are junk blacklist and junk whitelist and I added actually two addresses to the former. I will post again if I continue to have problems from these people.