For those of you who no longer find legendary blacklist SPEWS useful, you may want to have a look at APEWS, which has been running for several weeks now.
Although APEWS copies SPEWS in many respects, there is at least one architectural difference: level 1 does not list IP addresses or networks, but domain names, and level 2 is therefore not included in level 1. Nevertheless, level 1 is still intended to contain hardcore junk mailers; level 2 is more likely to cause false positives.
Both APEWS levels are included on Jeff Makey’s Blacklists Compared page.
Please share your APEWS experiences – post a comment!