Basically a call to operators to adopt a consistent forward and reverse DNS naming pattern for their mailservers, static IP netblocks, dynamic IP netblocks etc.
...and to ISPs to facilitate the process by supporting their users who want to run mail servers, and helping the rest of us use such techniques to quarantine the spew from zombies and less conscientious mail admins.
I'm always willing to be educated on why it is impossible for any given ISP to maintain an in-addr.arpa zone with PTRs for their customers who wish to be treated like real admins, as opposed to casual consumer-grade users with dynamically assigned addresses.
The problem is it is easier to set it up with a single standard 4-3-2-1.dialup.xyzisp.com then to change the IN-ADDR to mail.customer2.com. I only have an rDNS entry on the box at home because I used to work for the ISP. It's still there only because they probably haven't noticed, and will not until I draw attention to it or I give up the space if I cancel service. Still, it took me 3 minutes to put rDNS on most of 7 of 16 in my /28. It existed in their provisioning system to do it, but no one knew how. We couldn't even market it as a service, because it "didn't exist" in the system. I can't imagine, though, SBC being able to cope with tens of thousands of small business DSL accounts suddenly needing rDNS on their static IP's. Another question, though, is how they handle IN-ADDR and swip for dedicated circuits. If they can do it for a T1 customer, can they do it for a DSL customer? Maybe an online form the customer can maintain? Lord knows that would be better then trying to call their DSL tech support . . . Joe Johnson