The DNSBL Effectiveness Study: Measuring Real-World Impact of Community-Driven Blocklists

Abstract

A controlled study measuring the effectiveness of the vspam.org DNSBL feed across 2,400 participating mail servers over 60 days. We analyze false positive rates, detection latency, and the impact of trust-tier weighted voting on blocklist accuracy.

Key Findings

1. 1DNSBL feed blocked 94.7% of phishing emails within 2 hours of community confirmation
2. 2False positive rate measured at 0.003% across 2,400 participating mail servers
3. 3Trust-tier weighted voting reduced false confirmations by 67% compared to simple majority voting
4. 4Median detection-to-blocklist latency: 47 minutes for Tier 2 (Trusted) reporter submissions
5. 5Combined with existing RBLs, vspam.org DNSBL provided 12% additional unique threat coverage

Topics