Here some results of some 'unconventional' rbl that worked great in my system,
I tested spam/ham in the most true mode possible, adding the score that each
rule give to consider a spam in count
For example, if a rule that have a score of 5 i count spam emails that have
this rule and a score of 4
I'm pretty sure McAfee's DNSBL is just a mirror of Spamhaus Zen, which
of course is highly effective. I'm a bit wary of psky. Delisting is
"coming soon", and it's not clear who is behind it.
I am using the NiX DNSBL as well as their ixhash service and they both
work well for me. I am also using al