What are the main anti-abuse networks?

**Spamhaus** is the most influential anti-abuse organization, operating blocklists (**SBL**, **XBL**, **DBL**) used by most major MBPs. Getting listed on **Spamhaus** severely impacts deliverability globally. They track known spam operations, botnets, and compromised infrastructure.

Other significant networks include **Barracuda** (**BRBL**), **SURBL** (URI-based blocking), **Talos Intelligence** (Cisco's threat intelligence), and **Validity**'s reputation data (formerly **Return Path**). Each maintains databases of problematic senders, IPs, and domains that MBPs query during filtering.

These networks share intelligence with each other and with MBPs through formal and informal channels. When one detects a spam campaign, that intelligence propagates across the ecosystem. This collaboration enables rapid response to emerging threats but also means reputation problems spread quickly.