I'm trying to setup my own custom dnsbl server for blocking spam. I have successfully created a server running rbldnsd but am curious about what DNS records I would need to have in place so that my content filter can locate and communicate with the dnsbl...
For example, lets say that my dnsbl server has an ip of 123.123.123.123 and I want my content filter to be able to specify the dnsbl server as server.dnsbl.foo.com
Would I need to have an NS record pointing dnsbl.foo.com to the blocklist server? Or would I just need an A record in the foo.com zone pointing server.dnsbl.foo.com to 123.123.123.123?
Lastly, are there any RFCs for dnsbls? I'd like to understand the play-by-play for how content filters are supposed to request this type of information.
Thanks!