This RBL is compareable to ix.dnsbl.manitu.net, which itself is a list built upon a datafeed provided by the NiX Spam project of iX author Bert Ungerer.
I wrote a script that downloads the files nixspam.blackmatches and nixspam.cachematches in a 15 minute interval and imports them into a PostgreSQL database. My script also counts how often an IP or hash appears with different timestamps. On the first occurance an IP or hash will be listed for 96 hours. Unlike the original RBL, each additional time an email from the same IP or with the same hash is caught by an iX spamtrap, the timecounter resets and another 24 hours of listingtime will be added on top. If your IP or hash does not get caught in a spamtrap for 30 consecutive days, its record is being deleted.
The zone is being served by rbldnsd for maximum performance.
