If you want to use a 3rd party service to scrub bounces, etc, you get what you pay for:
SiftLogic - Removes known screamers and other "bad" domains and addresses, scrubs hardbounces, and rates the addresses based on their likely engagement. Price is tolerable.
BrightVerify - Same as SiftLogic but doesn't rate engagement. These guys are used by some big names in the bulk email space, but their pricing is painful.
ImpressionWise - Now claims to provide engagement info, and they claim to be the best at identifying sp*mh*us traps and other honeypots based on a whole bunch of heuristics for network analysis. The can only do this for GI data, though. They are totally unable to it for normal mailbox providers (yahoo, gmail, hotmail, etc).
I've personally worked with two out of those three, but all three are fairly well known.