I think we need an informational RFC that specifies best-practices for
a DNS{B,W}L to inform clients that they have been blocked.
For example, a testpoint like:
blocked.dnsbl.example.org
could return an A record for name servers that are blocked and NXDOMAIN
for others. This might even work out-of-the-box for some existing lists
that return an A record for any query (or it may not, if they expect
a reverse-dotted-quad.)
It could even return a TXT record giving the reason for the block.
Anyway, assuming this idea is widely-accepted (hahaha!), it would be pretty
easy to make something that periodically tests your list of DNSBLs and
disables those that are blocking your query.
Regards,
David.
