List of reliable RBL that we use internally and recommend to our customers.
Here goes:
zen.spamhaus.org
bl.spamcop.net
combined.njabl.org
cbl.abuseat.org
combined.rbl.msrbl.net
psbl.surriel.com
b.barracudacentral.org
With these RBL, combined with greylisting and a good SpamAssassin ruleset, out of combined 50,000 - 55,000 incoming email attempts daily on all SMTP servers that we monitor, only 0.05% of spam managed pass through. Pretty good!
