Blacklists, Blocklists, DNSBL's, and survival: How to survive as a ... RBL servers DNS-based Blocklists (DNSBLs) such as the Spamhaus XBL are designed only for use on mail servers. failure to execute an unsubscribe request, - the CBL (Composite Block List) from cbl.abuseat.org - the NJABL (Not Just Another Bogus List) Open Proxy IPs list from www.njabl.org. Spamhaus Advisory Better Business Bureau (BBB) McAfee SiteAdvisor.com