Thanks Charlie!!!
I had one of them configured.
We have this by default on SME8
more /etc/e-smith/db/configuration/defaults/qpsmtpd/RBLList
bl.spamcop.net:dnsbl.ahbl.org:dnsbl-1.uceprotect.net:dnsbl-2.uceprotect.net:psbl.surriel.com:zen.spamhaus.org
and on SME9
[root@www migrate]# more /etc/e-smith-release
SME Server release 9.0beta4
[root@www migrate]# more /etc/e-smith/db/configuration/defaults/qpsmtpd/RBLList
bl.spamcop.net:combined.njabl.org:dnsbl.ahbl.org:dnsbl-1.uceprotect.net:dnsbl-2.uceprotect.net:list.dsbl.org:multihop.dsbl.org:psbl.
surriel.com:zen.spamhaus.org
So we need to remove those from the defaults, and also add dnsbl.ahbl.org to the 20RBLList migrate fragment.
Is there more to it than that?