🚀 go-pugleaf

t strikes me that if anything is going to "rewrite" a field in a header,
it should construct a new field, not modify the existing one.  It is
important for the original fields in the message to be left intact.  As
it is, the Return-Path: field is, in essence, a rewrite of the From:
field.  "Smart" mailers sort of assume that the sender and recipient of
mail that passes through them aren't going to understand the headers
unless the "smart" mailers kindly rewrite them a little so that the
dumber sites will understand.  I don't think that is the place of a mailer.

A mailer should look at the beginning and the end of an address.  If the
address is in bang format (or mixed format and that site is bang-precedent)
and determine if it has heard of the site-name mentioned.  If so, send it
there.  If the address is in domain or internet notation, look after the
last @ in the address.  If I see @site that I recognize, I send it there.
If the top-level domain is one that I recognize, I send it there.
Regardless of the sub-domains.  That is for the mailer at top-domain to
figure out.  The sender of the message knows what address will "work"
through a site, and sends the appropriate address.  The mailer just sends
the mail if it recognizes the site name.  That is the way mail works now,
and will always work.  I know that if I send mail to
decwrl!"shannon@Xerox.ARPA" I can force bang precedence, and decwrl can
be fooled into delivering my mail to Xerox.  Which is what I want, and
I should be able to count on decwrl to do it.  If I can fix my mailer
to understand decwrl!shannon@Xerox.ARPA without the quotes, then I get
a pat on the back, but it shouldn't affect anything else.

We're never going to "fix" mail so that a person doesn't need to "know"
the appropriate address to send mail to.  The question "what is your
mail address?" will always be asked, and will always be valid.  Learning
a route is no harder than learning how to get mail to a smart mailer,
anyhow.

Sorry--I'm rambling a bit.
Glenn Reid
 ...{decwrl,glacier}!adobe!greid
-- 
You have new mail.