2 Questions; Add a Mac? and Generalize an EMail block list?

So the first: Replaced one of my 3 PC's with a Mac, can I deactivate the PC, and activate on the Mac, or do I need to buy a whole separate License for the Mac?

 

And the Second: I have somehow Ended up on some super Spam list, and am getting slammed (20-30 a day) with emails from Chinese chemical companies. Most of them have "Chem" in their domain names.  I tried putting *chem*.com on my blacklist, but either the old DOS Astrix placeholder doesn't work, or I did it wrong.  any advice (This method or another) on how to solve this?

 

Thanks!