🚀 go-pugleaf

chip@chinacat.Unicom.COM (Chip Rosenthal) writes:
> One of the things I'm assuming is that most dumb (uucp) sites are going
> to use From_ to route a return message while a smart site is going to use
> From:.  My thinking is that if sites would leave From: alone and update
> From_, then things would work.

This sounds like an excellent distinction.  But if the From: line contains
a bang address, it should still be updated for consistency.  If the message
is going to another UUCP site, the From: address should get prefixed with
the name of the current site; and if it's going onto the Internet, it
should get @current.site appended to it.

Actually, it can be optimized a little more, so that if the From: line
begins with a "fqdn!", you use that in place of the current.site.

> ... I might be confused in thinking that
> dumb uucp mailers are using From_ instead of From: to route replies.  If
> so, please do correct me.

Personally, I think you're right about that.  There's another thing I
worry about - what happens to the From_ line when a message enters and
leaves the Internet?  Do SMTP-->UUCP gateways use the contents of the
From: line to generate the From_ line, or do they use the MAIL FROM:<>
address from the SMTP handshake, or what?  If the From_ line gets
generated from scratch (">From daemon <timestamp> remote from <myname>"),
that would screw up the old mailers.  Or does the From_ line actually
go over SMTP?

Actually, there's another potential problem.  Are there any dumb UUCP
mailers that stick "myname!" onto the front of From: addresses that
already have an "@" in them?

If none of these things are problems, here's the way it should work:

UUCP->Internet gateway

	If the From: line is ...@f.q.d.n, leave it alone
	If the From: line is f.q.d.n!... change it to ...@f.q.d.n
	Otherwise append "@current.host" to it.

Internet->UUCP gateway

	Leave the From: line, user@f.q.d.n, alone
	(If necessary) build the From_ line from the From: line
		">From f.q.d.n!user <timestamp> remote from <myname>"

UUCP->UUCP transfers:

	Always do the right thing to the From_ line
	If the From: line has an @ in it, leave it alone
	Otherwise put <myname>! at the front of it

There are some uglinesses here that could be made to go away if you know
something about the receiving site.  All this assumes ignorance on the
part of the sending system.

> Dumb sites would have a From_ with a full
> path back to the sender, and smart sites would have an untarnished From:
> to work with.

Just so.

[Re: UUNET's munging]
> and even*after*requesting to be put on the list I'm still getting my
> incoming From:'s munged.

When we got ourselves moved onto the "smart" list, the change didn't kick
in until the next time UUNET restarted its sendmail, which was several
days later.

---
Tom Fitzgerald      Wang Labs           fitz@wang.com
1-508-967-5278      Lowell MA, USA      ...!uunet!wang!fitz