where can I find a list of all dynamic addresses out there?

[Jasen]

This isn't completely Sendmail related, but I ask here because I need it for my sendmail server. The title is probably confusing, so let me exlain. I know that many ISP's reject all mail that comes from dynamic/dhcp ranges. Apparenly they know which IP's say Comcast uses for it's cable customers, and which IP's it uses for it's own servers, and they block any mail coming from one of these dhcp ranges. This cuts out spam coming from botnets/zombies/worm infected home PC's.
Some of my users have a huge spam problem. Probably their own fault, I'm sure, but I would like to do as much as I can to kill it on our end. I'm already blocking about half of Europe, and probably most all of Asia at the firewall, and that killed probably 85% of the problem. Now I'd like to find where they get this global list of DHCP addresses from. I'm hoping it exists, and isn't proprietary information they have to gather themselves.
Anyone have an idea?

 

[RhythmAce]

You may want to look into spamassassin and clamav. Spam assassin looks at both the ip and content to determine whether it is spam. You can add more filters as needed and can choose whether to mark the mail as [SPAM] or delete it. Clamav is anti-virus software that can be set to check all files on your server as well as e-mail. I also use a catch-all for each domain so if their is no exact match for a legitimate user, it falls through to the catch-all and from there you can do what ever you want.