The DUL list is extremely useful. J.D. can correct me if I am wrong, but they don't do any probing with this list; they just list the IPs that are in dialup pools. It doesn't matter if they have an open relay or no mail server at all. Since there's rarely any legitimate reason for someone to be sending mail from a mail server on a dialup line, this easily blocks a large source of spam with little risk.
More to the point, they only list IP networks that the administrator of the network has _asked_ them to list. This list is a voluntary opt-in on the part of the ISP in question. -- Joe Rhett Chief Technology Officer JRhett@ISite.Net ISite Services, Inc. PGP keys and contact information: http://www.noc.isite.net/Staff/