Q: Can I block emails from a specific email address on my @me.com account?

Yes.  You can set up an email rule on icloud.com that will direct incoming mail from a specific sender to the trash or another folder of your choice.  This article explains how, under "Set up rules to filter emal": http://help.apple.com/icloud/#/mm6b1a3f8a.

I also tried to set up a rule for one email address to have it sent elsewhere as a way to block that sender from my email....it now has sent all of my email from my icoud account to the address I wanted the 1 sent to from a specific sender.  Why is that?