> > His mate is a wise man. RBLs are a really terrible idea, and > > they've caused a lot of valid mail to be rejected. There's really > > no way to reliably determine that a message is spam based on the IP > > address or sender's domain name. The most you should do with RBLs > > is delay or rate-limit mail from the blacklisted sites, you should > > never reject such mail. > > .. > > It's never clear to me what Keith Moore means by "RBL" when he repeats > that claim. Those three letters are a registered service mark for a > product that historically has been run so conservatively that claims > that should not be used to reject mail sound silly. Yes, "RBL" did indeed reject valid mail, because it misled site administrators into thinking that mailers that failed its test were inherently able to be exploited into relaying significant amounts of spam. So sites that trusted RBL's misrepresentation blocked valid mail from sites that rate-limited relayed mail (including the site I ran at one time) even when that rate-limiting was an effective spam block. I really have no sympathy for net vigilanties who insist on trying to enforce their own narrow-minded definitions for how the net should work, and who disrupt others' service in the process.