One thing I notice is that the IP addresses of blacklisted domains are not always listed in the BL as well.
For example, when I look up:
ghcclccc.biz.multi.surbl.org
It's listed. However, when I look up:
72.2.139.221.multi.surbl.org
it's not listed.
Might I suggest that all domains listed in the BL also include corresponding IP addresses?
--Dave