Denny Lin wrote on 10/20/2010:
Currently, I am using a setup with Postfix + Dovecot as well.We're using these DNSBL blacklists: zen.spamhaus.org b.barracudacentral.org cbl.abuseat.org bl.spamcop.net dnsbl.njabl.org
info:it's not needed to use cbl.abuseat.org AND zen.spamhaus.org because the data from cbl is included in zen.
Link: http://cbl.abuseat.org/faq.html -- Daniel