What is Spamhaus?

Spamhaus is the most influential anti-spam organization, operating blocklists used by the majority of internet email systems. Founded in 1998, it tracks known spam operations, botnets, and compromised infrastructure globally.

Spamhaus blocklists include: SBL (Spamhaus Block List) for verified spam sources, XBL (Exploits Block List) for compromised systems, PBL (Policy Block List) for dynamic/residential IPs, and DBL (Domain Block List) for spam-associated domains.

Getting listed on Spamhaus severely impacts deliverability across most MBPs. Delisting requires demonstrating the problem is resolved. Spamhaus provides self-removal for some listings but may require manual review for serious cases. Avoiding Spamhaus listing through good practices is far easier than remediation.