Spamhaus is helping us get our total query count down by moving some of their checks to the SMTP-level and rejecting on that rather than letting rSpamd do all the queries.

Curently, SmarterMail can only do checks against their zen.dq.spamhaus.net list. However, they are also wanting us to query the sender domain, the helo hostname and the reverse hostname of the IP address.

Since SM can only do queries for the IP address, Spamhaus is telling us to move to Postfix as it offers more flexibility with the reject_rhsbl_sender, reject_rhsbl_helo and reject_rhsbl_reverse_client options.

We'd like to avoid going to postfix if possible.