Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!julius.cs.uiuc.edu!apple!mips!daver!tscs!tct!chip From: chip@tct.uucp (Chip Salzenberg) Newsgroups: comp.mail.misc Subject: Re: Which headers may Sendmail re-write? Message-ID: <27763742.4907@tct.uucp> Date: 24 Dec 90 17:13:37 GMT References: <1990Dec19.171943.18595@chinet.chi.il.us> <27710AE7.1356@tct.uucp> <1990Dec21.193938.29940@chinet.chi.il.us> Organization: Teltronics/TCT, Sarasota, FL Lines: 38 According to les@chinet.chi.il.us (Leslie Mikesell): >In practice, it should be pretty rare that the recipient's response >should go a different route than an error return. Presumed rarity is not an argument against allowing for such a difference. In any case, it is *usually* true here that replies should go a different route, for these reasons: 1. Group replies. 2. Avoiding unreliable sites. 3. Avoiding rabid rerouters (rutgers and bionet). 4. Avoiding Mail Header Mungers From Hell (apple.com). 5. Avoiding pessimal paths generated by sites that aren't using up-to-date maps. For all these reasons, I will always use Reply-To: and From: addresses -- or if they've been munged, signature addresses -- rather than the From_ line. The From_ line is unsuitable anyway, because it is a path to the *sender*, who is not necessarily the user to whom replies should be sent. Thus, to get back to our original subject, it is Evil and Rude to mung an RFC822 address from user@valid.domain into valid.domain!user, because such munging renders impossible the *correct* handling of replies for RFC822-aware but UUCP-only sites. >Using !-notation for the addressing is not at odds with paths routing, >though. In itself, no. But, as you note in an unquoted portion of your article, bang notation is relative, whereas RFC822 notation is absolute. Thus @-to-! translation is a semantic change, not just a syntactic one. Therefore, gratuitous conversion of addresses from absolute to relative is (all together, now): Evil and Rude. -- Chip Salzenberg at Teltronics/TCT , "Please don't send me any more of yer scandalous email, Mr. Salzenberg..." -- Bruce Becker