Most Public DNS resolvers do not work with spamhaus.org RBL, are there any that do?
OpenDNS resolvers generally make too many queries and do not allow DNSBLS and URIBLS. OpenDNS has an article that adds further context to this: Does OpenDNS Work with DNSBLS and URIBLS?
Spamhaus also offers a free service for non-profits and non-commercial use. "Spamhaus provides the public with free threat intelligence; helping small independent businesses, schools and non-profit organizations safely filter their email at no cost." The three requirements are:
- These block lists are to be used ONLY for non-commercial purposes*
- Your email traffic totals fewer than 100,000 SMTP connections per day
- Your query volumes total fewer than 300,000 queries per day
For additional information, please review FREE Data Query Service Account