+# need to use this sublist due to taint
+hostlist goodhosts = *.$sender_address_domain : $sender_address_domain : \
+ ${lookup dnsdb{>:defer_never,mxh=$sender_address_domain}}
+
+.ifdef DNS_RECURSE
+hosts_treat_as_local = test.again.dns
+domainlist try_again_dns_list = @mx_any
+dns_again_means_nonexist = !+try_again_dns_list
+# that last line tries to set up a recursion
+.else
+dns_again_means_nonexist = *
+.endif
+