🚀 go-pugleaf

In article <1697@ucsd.EDU> brian@ucsd.edu (Brian Kantor) writes:
>BTW, some sites currently passing mail are using the original
>mongo-stupid Unix mailer that doesn't even know what a From: line IS,
>much less how to update it.  Mail passing through these sites is
>fated to be terminally mangled and probably can't be replied to.  All
>you can really do about this is warn your users and avoid those sites.

On the contrary.  Such mailers are correct, it is Berkeley who screwed
the world by putting bang paths in the From: header!  A mailer that
doesn't know what a From: header is has the virtue that it never messes
one up.  The only mailers harmed by dumb UUCP mailers not updating From:
lines are those that attempt, INCORRECTLY, to use the From: line as a
relative bang path.

Dumb UUCP mailers, UUCP sites running smail, RFC976-compliant UUCP-Internet
gateways, and Internet sites can all get along beautifully.  Note that
none of these guys alter a From: header if one is already present.

In this perfect world, someone with a plain-vanilla UUCP mailer would
mail to

     foo!bar!biff!uunet!bilbo.bigschool.edu!user

and not include a From: header at all.  As long as mail passes through
vanilla UUCP sites, no From: header is generated.  When it is necessary
to generate a From: line (at the gateway, or at the first registered
domain site), we make one:

       From: foo!bar!sender@localsite.domain

Yes, it's mixed, but since only RFC-822-compliant sites read From: lines
there is no possible ambiguity: the "@" takes priority.

Going in the other direction (from Internet to UUCP-land) there is also
no need to rewrite the From: line.  We must generate a From_ line, but
thanks to RFC976 that is easy:

 From bilbo.bigschool.edu!user Mon May  8 16:02:45 1989 remote from gateway

Unfortunately, it is too late to save the world.  Berkeley has already
wrecked things by releasing sendmail to the world and encouraging every
site admin with too much time on his or her hands to hack away at it,
and the original sendmail had no way of doing the correct thing to both
the From_ line and the From: line at the same time.

Given the world we're in, Brian (in the part of the article I didn't quote)
is right: if you get a From: header with no @ in it, you'll need to rewrite
it.  But it is the mailers that generate such things that are in error,
not the vanilla V7 Unix mailers, which can be made to interoperate with
the rest of the world quite nicely.

-- 
-- Joe Buck	jbuck@epimass.epi.com, uunet!epimass.epi.com!jbuck