Is there a way to block emails by a language in Horde?

I am trying to get rid of one spammer that sends 5-10 emails every day. They are in one of the Asian languages. The problem is it's always a different handle and domain, so when I blacklist one email address, they send another one from a different domain / handle. I'd like to block the entire language. Do you think there's a way of doing that?

 

Hi.

Have you tried to use SpamAssassin?

 

Why did I not think of that? Thank you. Enabled!