msir_ltd@ur-tut (Mark Sirota) (04/07/88)
Since the case of x!y@z is ambiguous, isn't the right thing to do to bounce the letter, preferably with a message stating that the address is ambiguous? The fault can be attributed to whoever generated the address, so why not just send it back? This seems like the right thing to do; At least the sender will *know* what happened to the letter, rather than having it potentially get lost at a bad address. Aren't there other ambiguous cases? I can't think of any off the top of my head, but what do people usually do with ambiguous addresses? -- Mark Sirota msir_ltd%tut.cc.rochester.edu@cs.rochester.edu (rochester!ur-tut!msir_ltd)
diamant@hpfclp.HP.COM (John Diamant) (04/07/88)
> An optimal solution may be to parse "x!y@z" both ways and determine > which of the hosts z and x are known by the local host. This provides > a way of disambiguating the syntax. Yes, Peter Honeyman wrote a paper on doing just that (including heuristics to disambiguate in case there wasn't an obvious answer in terms of simple connectivity). It's entertaining reading, but frankly, I think this is a very bad idea in practice. Basically, the only solution is to resolve the issues at the RFC level and get everybody fixed up who does it wrong. RFC976 and smail is a very good pass at it, but even in that case, it has some problems with embedded "%" in the case of an unregistered machine (one without a proper domain address). If everyone gets domain addresses, the problem disappears (as long as RFC976 and the other RFCs are obeyed). John Diamant SDE UUCP: {hplabs,hpfcla}!hpfclp!diamant Hewlett-Packard Co. ARPA Internet: diamant%hpfclp@hplabs.HP.COM Fort Collins, CO