If it helps, here's what I wrote for the SURBL FAQ: http://www.surbl.org/faq.html#opendns
I'm using OpenDNS and getting wrong answers to SURBL DNS queries OpenDNS is a service that changes the responses to some DNS queries in order to prevent users from visiting spam, phishing, etc., sites. It also has a "typo correction" feature that directs mistyped domain names to custom sites controlled by OpenDNS instead of sites controlled by typosquatters, phishers, etc. When using SURBLs with an OpenDNS nameserver it's important to disable the typo correction feature, or the responses to non-matching SURBL queries will be incorrect to a SURBL application. The reason is that the OpenDNS nameservers return an IP address of their own web site in those cases, and that modified IP address will have an incorrect effect on SURBL list identification that depends on where the bit patterns happen to be in the modified response. SURBLs will work with OpenDNS if their typo correction feature is disabled on servers or clients doing SURBL queries. Alternatively, consider using non-OpenDNS nameservers on those systems. Note also that SURBL applications may be incompatible with other DNS modification or proxy services that change the DNS query results of non-matches (NXDOMAIN results). Jeff C. -- Jeff Chan mailto:[EMAIL PROTECTED] http://www.surbl.org/
