How can I reduce spam to my @mac.com email address?

I have an @mac.com email address that I've been using for over ten years. In the last year or so I transitioned from using a Mac OS X computer to using iOS devices exclusively. I'm guessing the OS X Mail app had some kind of built-in spam-removal capabilities, because I now receive a ton of spam on my @mac.com account. At best it's not too bad, I'd say a couple of spam emails a month. However it randomly spikes up really badly, for example in the last couple of weeks I've been receiving about 20 spam emails daily.

I move every spam email I get to the Junk folder in iOS Mail. Is there anything further I can do to reduce the amount of spam email I get? I've seen a couple of third-party apps on the App Store, but reviews have been mixed. My guess on the overall situation is that Apple simply doesn't devote the resources that other email providers do (Google specifically) to server-side spam removal.

Thoughts?