Path: utzoo!attcan!telly!problem!compus!lethe!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ames!ncar!midway!gargoyle!chinet!les
From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: comp.mail.misc
Subject: Re: Which headers may Sendmail re-write?
Message-ID: <1990Dec14.233316.11292@chinet.chi.il.us>
Date: 14 Dec 90 23:33:16 GMT
References: <KARL.90Dec13123956@giza.cis.ohio-state.edu> <1990Dec14.064837.8996@Latour.Sandelman.OCUnix.On.Ca> <1990Dec14.174541.14252@Think.COM>
Organization: Chinet - Public Access UNIX
Lines: 27

In article <1990Dec14.174541.14252@Think.COM> barmar@think.com (Barry Margolin) writes:

>Sendmail is an application-level protocol-translating gateway.  There
>wouldn't be much controversy over an SMTP<->X.400 gateway munging headers;
>it's an obvious part of the job.  Why do you expect less of a UUCP<->SMTP
>gateway?  The header requirements and interpretation mechanisms of the two
>protocols are not identical, and it is the job of a gateway to transform a
>message coming in via one protocol into a valid message for the other
>protocol.

I think there will be controversy if the SMTP<->X.400 gateways can't
invert the necessary mappings.  That is, if one SMTP host sends
to an X.400 forwarder who sends to another host that sends by SMTP
to the destination and the headers are no longer usable.
This appears to be the case that people are complaining about with
the UUCP<->SMTP gateways.  The munging necessary to keep the internet
happy is not being done in a way that allows it to be undone at the
other end, nor is there any way for the original munger to know
what form the recipient wants (how, for example would you know
that les@fb.com is 3 uucp hops off the internet and would greatly
prefer to see From: les@chinet.uucp rather than
 From: chinet!les@some.domain?).   The latter form is likely to
undergo some very strange transformations along the way that
you internet people never see.

Les Mikesell
  les@chinet.chi.il.us