dredd@megacity.org (Derek Balling) writes:

I think (as I interpret the discussion) it is this way:

Anyone can do whatever he wants with his/her mail server.

well, sort of. any mail server operator's freedom stops at the edge of any other's. that is, a spammer cannot do whatever he/she wants with his/her mail server since one of the things they want to do is connect to my mail server and dump spam on me. i think you meant "any mail server operator is free to reject any traffic they want to reject, for any reason or for no reason." and i'd agree with that formulation. but maybe that's not what you meant at all, because:

The Network Operator can do whatever he wants with his network, BUT if the network provider has downstream customers, paying for internet connectivity, and the operator filters out part of that connectivity, then the operator has voided the contract (by filtering out a portion of the network the downstream may consider "important") in a manner that allows the downstream to bail out of any such contract. (I think such a filter could be considered "materially altering the service provided" although IANAL).

because people in the service business are so liable for so many things, they usually employ the services of actual, honest-to-god lawyers. and so, when you visit a food-serving point of sale ("a restaurant") in california you can usually learn by simply looking at the front door that they "reserve the right to refuse service to anyone." and so, the transit contracts i've signed (from either side) virtually all leave "wriggle room" for things like running the MAPS (LLC) RBL (tm) in BGP mode on all backbone routers. of the couple of worldwide ISP's i know of who do that, every one of them tells their customers up front that they're doing it, and none of them seem to be lacking for new customers. but as JD also noted, there's a discrepency in the above summary. one thing that mail server operators do increasingly often is to run the MAPS (LLC) RBL (tm) in DNS mode. hotmail started doing this recently. this certainly qualifies under the "allowed to refuse traffic for any reason or no reason" formulation of the first policy, but seems to run afoul of the "filtering out important destinations" rule described in the second policy. pretty much what happens is that most ISP's are like california's restaurants and they reserve the right to refuse service to anyone, including spammers. -- Paul Vixie <vixie@mibh.net> >> But what *IS* the internet? > It's the largest equivalence class in the reflexive transitive > symmetric closure of the relationship "can be reached by an IP > packet from". --Seth Breidbart