We are currently building up a new method to report spam from dnswl.org-listed IP addresses. It will allow you to simply copy&paste (in the future: forward by email) spam you received.
If you would like to participate, please contact us at admins /at/ dnswl.org to get a login to the reporting interface. You can also join our (low volume) public mailing list for discussions around this feature.
Not every single spam may result in a direct action (eg lowering a score) but it is important for us to get unambiguous feedback to judge the trustworthiness of an entry in our database.
Please note that we are not, like eg Spamcop, a generic abuse reporting service, but can only act on entries listed in our database.