dnsbl.ze-filter.org is a “poor's man reputation list” which can be used with ze-filter, as explained here.
Entries in this list are best described as end-users, or home users: customers who are not supposed to send out emails directly, and even if they do, they are not supposed to send large amount of emails. List consists of IP addresses or hostnames matching some regular pattern which indicates that they're associated to residential lines (or similar) : ADSL, dial-up lines, etc, for instance: *.fixip.someisp.tld.
This is one of the criteria used by some major blacklists, such as mail-abuse.com DUL. Although they say that only dynamically assigned addresses are listed, this isn't true, as they also list ADSL with statically assigned addresses.
The list is built with a set of scripts which does some number of checks on hostnames, IP addresses, …. As long as this is an automated process, errors may exist and in fact exist. But, despite of some errors, this shall not be a big problem if this list is used only to impose reduced limits and not reject connections.
NetClass, in order to not impose so tight limits to your own users.
To use this reputation list with ze-filter, define the following at
/etc/ze-filter/ze-tables (it's already in the default configuration).
<DNS-IP-RBWL> dnsbl.ze-filter.org netclass=dnsbl; odds=2.0000; code=all; onmatch=stop; checks=addr,name </DNS-IP-RBWL>