What do you suggest for blocking foreign character spam?

Yahoo advises me they have no solution to blocking foreign character spam? How is that possible? I get hundreds of spam messages with characters I cannot recognize and want them to go in the trash upon arrival. Can I use an outside spam filter like Spam asin in conjunction with Yahoo's spam filter. I have no idea if that works, or whether there are other work arounds. I'm sure I am not the only one in the US receiving all this crap.