Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!wang!fitz From: fitz@wang.com (Tom Fitzgerald) Newsgroups: comp.mail.uucp Subject: Re: Paths and Precedence (Re: Question about From: lines) Message-ID: Date: 29 Jun 90 22:42:53 GMT References: <2833.2674c5b3@mccall.com> <14298@ucsd.Edu> <2836.26750678@mccall.com> <14423@ucsd.Edu> <00001FL@cdis-1.compu.com> <2999.2688d45c@mccall.com> Organization: Wang Labs, Lowell MA, USA Lines: 30 peter@ficc.ferranti.com (Peter da Silva) writes: > I have a question about paths. What's the official word on % versus !? I'm > currently implementing things so that % has tighter binding than !, and @ > has looser > Is this a reasonable interpretation? It's reasonable in the sense that it will make things work right, but unfortunately it violates RFC1123 section 5.2.16, which says that ! should bind tighter than %. This is actually an unfortunate choice. As more and more sites become compliant with it, the use of %-addresses from UUCP sites becomes less and less reliable. I've started telling people here never to use addresses with %'s in them, because they rarely work. The problem is that, under smail 2.5 (and, I believe, uumail), addresses like a%b@c get rewritten to path!to!c!a%b and sent out onto the UUCP net. This works as long as 'path' and 'to' disobey RFC1123. If either of them follow it and interpret c!a%b as (c!a)%b, the message will get lost. Smail 3.1 avoids this problem by rewriting a%b as b!a in outgoing mail, but even the authors point out that it involves rewriting the local parts of nonlocal addresses, which isn't always such a great idea. In this case, however, it does make things work right. --- Tom Fitzgerald Wang Labs fitz@wang.com 1-508-967-5278 Lowell MA, USA ...!uunet!wang!fitz