🚀 go-pugleaf

Our rmail has been taught to believe that any bangist address in a From:
line arriving via uucp is likely to be wrong, so it substitutes the From_
path in place of it.  It also does that if there is no domain, the
domain is "uucp", or there is no From: line.

This is passed to sendmail, which converts the bangist path in the
arriving From: line to bangist!path@ucsd.edu (RFC822 compliant) for
internal processing, which is unaltered when the mail is sent out via
an SMTP connection, and which is converted to ucsd!bangist!path when
the mail is forwarded using uucp.

If the mail arriving via uucp contains a From: line like host@dom.ain,
rmail does not alter it at all before passing it to sendmail, and when it
leaves via uucp, we choose the greatest common denominator and issue it
as ucsd!dom.ain!host in the outgoing From: line, and as
"From dom.ain!host date remote from ucsd" in the uucp From line.

This provides the most widely-usable form of headers for people
forwarding mail through us.  It may thwart some attempts to use magic
routers for uucp (some cope, some don't), but few of our uucp
connections run them, since we provide that service.

I find this to be a good set of compromises, and on the whole,
satisfactory.

	Brian Kantor	UCSD Postmaster
		brian@ucsd.edu	BRIAN@UCSD ucsd!brian