RE: Blocking with RBLs

All these rbls are only acting on bulk, you won't prevent targetted abuse, and you also need to be able to whitelist. Best is to have your own rbls and centralised logging for your servers. The logging server adds ip ranges to your rbl and all servers use the rbl. But beware of clients that are misconfigured and create a false positive blocking everyone from that ip (like a business connection)