Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: notesnews 0.1 (unido 12/05/84); site unido.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!mcvax!unido!dfk From: dfk@unido.UUCP Newsgroups: net.mail Subject: Re: Mail routing -- problems showing up Message-ID: <11500001@unido.UUCP> Date: Fri, 26-Jul-85 23:55:00 EDT Article-I.D.: unido.11500001 Posted: Fri Jul 26 23:55:00 1985 Date-Received: Tue, 30-Jul-85 06:32:38 EDT References: <3018@nsc.UUCP> Sender: notes@unido.UUCP Lines: 98 Nf-ID: #R:nsc:-301800:unido:11500001:000:3616 Nf-From: unido!dfk Jul 27 01:55:00 1985 > /***** unido:net.mail / topaz!hedrick / 2:12 am Jul 24, 1985*/ > But more generally, I am not convinced that it is right to have > artificially-intelligent parsers that decide what foo!bar@baz means > based on the semantics of the addresses. I don't either. If we need these it means that the users who are supposed to understand the addresses couldn't cope either. It's sometimes difficult for myself although I am the local "postmaster". > Can't we just agree on some other character that has the > same meaning as @ (i.e. internet host), but with the same order as !. > Suppose we choose $. Then foo!bar@baz would become baz$foo!bar or > foo!baz$bar, depending upon what was meant. All of the UUCP/Internet > gateways should be running software powerful enough to convert between > this format to an RFC 821 format. I don't like that either. Why introduce a new symbol? I think you can solve that simply by knowing via wich net the mail did COME TO YOU. I use the general Rule: RFC822 (@/% precedence over !) if it is originated locally or comes via a network other than uucp. UUCP (! precedence over @/%) if it comes in via UUCP I have just made a new sendmail.cf including support programs for unido.uucp alias ddoinf6.bitnet. This is based on the work of Jim Crammond . It parses addresses according to RFC822 giving @ and % precedence over !. I find this works well and I tell my users to avaid !s. We have a rerouter so most addresses don't use an explicit path. I tell users to avoid mixing @/% with !s if they HAVE to specify a route. They can use foo%bar.arpa%seismo@mcvax or even (for persistent bangists) mcvax!seismo!bar.arpa!foo wich is understood by seismo. As Hedrick suggested: > So mail can be addressed topaz!blue!user rather than topaz!user@blue. How > common is this? If it is common enough, then we can just tell people > not to use @ in UUCP addresses, and forget this whole problem. That's what I do. Sticking to these rules makes sendmail.cf easier to do and to understand. BTW: Jim's stuff is generated from a set of files so you don't have to write a single rewriting rule! The one tricky problem is when you interface to uucp! Normal uucp mailers give ! precedence over @ wich is perfectly OK from their point of viewing addresses. General rule for uucp-mailers: Is there a bang in it? If yes, strip foo! and send to foo. If not, deliver locally (whatever that may mean). I have rewritten /bin/rmail to cope with this before sendmail even sees the address. It simply converts any mixed mode addresses to a single mode (in my case bangish) giving bangs precedence. So if I get mcvax!seismo!foo@bar.arpa it will turn it into mcvax!seismo!bar.arpa!foo and give it to sendmail. I think this is the only valid interpretation if something comes in via UUCP! It goes without saying that I convert all addresses to !-format deleting .uucp domains when I SEND something via uucp. Users at hosts "behind" unido know that they can simply say unido!foo@bar.arpa. If they insist on routing stuff the "don't mix modes" rule aplies. unido!mcvax!seismo!bar.arpa!foo. If they would want to do forbidden things they could do: unido!mcvax!seismo!bar.arpa!uucp1!uucp2!user I am not sure seismo will interpret that correctly but I strongly suspect it. I admit this was rather lengthy, so let me repeat the morale: 1) don't mix ! and @ 2) If you get a mixed address decide about precedence based on the network by which the message ARRIVES Comments welcome. -Daniel Karrenberg