SpamAssassin Rule: RCVD_IN_DNSWL_NONE
Standard description: Sender listed at http://www.dnswl.org/, no trust
dnswl.org is a community-driven project to prevent false positives. dnswl.org provides a DNS-based whitelist of known legitimate hosts in different categories/trust levels.
The policy says for trust level "None":
Legitimate mail server, may also send spam. This is the default for some categories (eg Email Marketing Provider)
IPs sending spam are expected to hit this rule, but if you get so many emails sending spam, and none sending non-spam, that you think it shouldn't be listed, you can report them here: http://www.dnswl.org/registerreporter.pl
As with many SpamAssassin network rules, it is important to make sure you have your trusted_networks / internal_networks (TrustPath) configured correctly to ensure that the test is run against the correct IP.
IPs that are not listed which should be can be reported here: http://www.dnswl.org/request.pl
You can also contact the maintainers of this data at email@example.com
The default scores for this rule can be found in the online list of tests.