I'd like to be able to publish DNS records announcing my domain's *outbound* mail servers, with nice abbreviated forms to say "they're the same as my inbound (MX) records" or "any IP in x.y.z/24". Then cooperative ISPs (like say America Online) could refuse any email from my domain that originated from some random cable modem, instead of accepting it and then flooding me with 20000 bounce messages.
It's almost to the point to where mail servers need their own "registrar", sort of the way domains are tracked now, track mail servers. Give mail server admins the option to accept mail from registered mail servers only or from any mail server. Of course there would need to be a ramp up period, like six months to a year, to make sure all of your mail servers are registered. And of course one should only be able to register mail servers if the IP space is actually SWIP to them. If the IP space is NOT SWIP, it would need to be registered by the customer ISP or via owners rwhois server. Just my $.02; for what it's worth.... -- Robert Blayzor, BOFH INOC, LLC rblayzor@inoc.net When all else fails, let a = 7. If that doesn't help, then read the manual.