The practice of spamming has grown at an alarming rate. The mechanics of creating and managing a blacklist of spammers haven't changed all that much, but the tooling around them has changed drastically. In this talk, we'll discuss how to create a DNS-based blacklist (DNSBL), what tools are available to do so, and how to manage the DNSBL once it's set up. Additionally, we'll discuss how to easily migrate and scale a legacy DNSBL system using Docker and PHP.