A distributed database tracks real-time information about connections to our servers and where spam and viruses are currently being sent from. This information is used to rate-limit mail from likely spammers and from emerging spam and virus sources. Rate-limiting is a safe way to reduce spam because mail is never blocked. Instead, mail is allowed through, but at a much lower rate. This permits legitimate mail to be delivered, while slowing down high-volume spammers.

This system also protects the KD Interactive Hosted Email servers from denial of service ("DoS") attacks by limiting the number of concurrent and successive connections third-party servers can make.