Android :: Creative Ideas For Stopping Email Spam?

I'm trying to help someone who'd like a way to stop email spam from reaching his Android phone. I understand this is usually best done from the email server side of things, but this is where we are right now. This is regarding his work email, and I've suggested that he have gmail fetch it for him so they can filter it (does this work for fetching? I know it works great for emails sent directly to gmail), alas, he says he only has an imap server and no Pop3 server for gmail to fetch. I looked in the market and found only one not terribly highly rated app for filtering email spam on Android phones. If you've tried that email filtering app, it worked?