sirrar,

Can you please ensure that in your MAPS RBL list, you have a ",true" suffix in the entry:

zen.spamhaus.org, true

The "true" indicates that the RBL wants to receive the IP octet in reverse order. Please also note that most RBL blacklists have the same requirement, so most of your blacklist entries should have the ",true" suffix in them. If incorrect, this will cause spam emails to go undetected, and also will cause some legitimate emails to be blocked, as the query will be performed not on the correct IP, but on the one with the reversed octets.

Sirrar,

You have several duplicates in the list, along with one that we recommended a few weeks ago to be removed as it's no longer active.

I strongly recommend you replace your list with only the following entries:

bl.spamcop.net, true
cbl.abuseat.org, true
combined.njabl.org, true
dnsbl.sorbs.net, true
zen.spamhaus.org, true