Yes! I took at look at your settings, and it looks like you've already blacklisted a couple .pw email addresses. On that same page in your panel (Anti-Spam > Edit Filter > email@example.com > Edit), you can add a custom blacklist for an entire domain:
FYI, you can blacklist domains and addresses "domain-wide"— that meaning that for ALL of YOUR addresses, you're setting the blacklist.
You can also blacklist domains and addresses "per email address"— that meaning that for solely one of your email addresses, you're setting the blacklist.
Hope that helps!