Who maintains blocklists (Spamhaus, Barracuda, etc.)?

Blocklists are maintained by various organizations with different structures and motivations. Understanding who operates each list helps navigate the delisting process.

Spamhaus is a nonprofit organization dedicated to anti-spam efforts. It is funded by industry partnerships and operates independently. Spamhaus has significant influence because major providers trust its data.

Barracuda maintains its reputation block list (BRBL) as part of its commercial security business. It serves both Barracuda customers and the broader community.

SpamCop, now owned by Cisco, operates based on user spam reports and automated analysis. Its listing criteria are more dynamic and responsive to immediate spam patterns.

Community-maintained lists like SORBS and various volunteer efforts also exist, though with varying levels of influence and maintenance.

Different maintainers have different standards and processes. Know who you are dealing with when seeking delisting.