i'm missing my copy of "why a wildcard MX won't help sitefinder"

at the meeting yesterday, verisign said they were considering the benefits of a wildcard MX RR whose target was a nonexistent name, as a way to keep smtp traffic from having to come to sitefinder for rejection. i recall a very good posting on this topic and i think it was on nanog but i can't find it now. can someone privately send it to me if you've got it? -- Paul Vixie