The idea here was to implement something like SpamAssassin 3.0's new
URIDNSBL test, though for SMTP-time details (e.g. do DNSBL lookups on the
name servers hosting the domain name of the return path, helo, relevant
in-addr.arpa space, etc) rather than for domain names found in the body of
the message.
I haven't actually tried this out myself, but the SA guys are reporting a
60% hit rate for URI nameserver SBL checks on their spam corpus, and
almost 0 hit rate on real email. Nice.
--
Tony Finch <dot@???>
http://dotat.at/