Thank you very much for the detailed and timely response! For the record I don't necessarily think that my web host is caching the lists, but that is why I asked about how that works, whether the list maintainers blocking IP ranges versus individual IPs, and the delays between spam being sent, repor...

Thank you for the followup and the information. Based on your advice, I started spot checking IP's against the reputation lists that I had manually blocked, that were getting through. So far, all of the IP's that I have checked are already on at least one list that I already have enabled in MagicSpa...

I have MagicSpam Pro enabled in cPanel on my web Linux based host, and recently started digging deeper to kill some of the spam that is still getting through. Specifically, I have started reviewing the HAM logs for the biggest offenders and putting their IP's in the "ip_blacklist.lst" file...