🚀 go-pugleaf

In article <16238@amdcad.AMD.COM> bandy@amdcad.UUCP (Andy Beals) writes:

Glossary for the newcomer.  In the following mail:
1	From uucp <date>
2	>From uucp <date> remote from mumble
3	>From bar <date> remote from foo
4	Date: <date>
5	From: bar@foo.com
The "From: line is the 5th line, the "From_" line (the "_" represents
a space) is the conglomeration of lines 1, 2, and 3, in effect becoming
the single line
1	From mumble!foo!bar <date>
(Some mail systems actually do this collapsing, others don't, it doesn't
matter.)

>Now that we have bsmtp, the answer is simple.

"We" may have BSMTP, but the fraction of net sites that support BSMTP
is pretty tiny.  The most widespread implementation has a serious
problem: it blindly throws the BSMTP file at sendmail -bs and hopes it
works - if anything goes wrong, the mail is thrown on the floor.  Because
of this, hardly anybody is using BSMTP today.  I sure won't write code
that assumes that everybody supports it properly.

>If you want your mail to work rather than be strictly correct according
>to the rules, prefix myhost! on the front of mail to your remote neighbours
>and send it via rmail.  Mail will go through because it's worked this
>way for years.

Nonsense.  "For years" what has worked has been the From_ line, which is
a working bang path on the whole net, no matter what software they run.
The only implementations that prepend myhost! on the From: line are 4.2BSD
and 4.3BSD.  System V doesn't.  V7 doesn't.  Xenix doesn't.  4BSD doesn't
if you run smail.  All the standards (822, 976) explicitly say you leave
the From: line in domain format - it is not and was never a bang path.

If your reply command wants a bang path, there's one sitting in the From_
line just waiting to be used.  There is no excuse for violating the
standards by scribbling on a valid domain From: line.

>Now, to all the hosts (leadsv, for example) that pass mail without adding
>myhost! to the front but don't pass mail via bsmtp, tisk tisk -- do you know
>how much mail you cause to bounce every day?  And don't tell me that it
>isn't so.. Being on the postmaster alias for a backbone site tends to show
>one which mail does and doesn't go through.

Any system that depends on *every host* in the path to update a header
line isn't worth its value in spare bits unless every host updates that
header line.  Everybody DOES update the From_ line.  Almost nobody updates
the From: line, and those that do only do so because they installed the
4.2 or 4.3 tape and haven't fixed it.  (An easy fix is to install smail.)

But don't go advocating that the 90% of the world that obeys the standards
suddenly break that conformance in order to try to prop up an undocumented
convention that never worked and duplicates an existing, working, documented
standard.

	Mark