Eh Rick, I found RFC1440 and read it. It wasn't exactly what I had in
mind, really. ...
Yes. And I didn't mean to get the thread side-tracked.
I rather see a multipart/uft with one part
application/uft containing the control stuff and a second part
containing the file to be transferred with proper content-type: and
content-transfer-encoding:.
Exactly. The protocol was intended to be "wrappable" in MIME
very much as you've outlined there.
Anyway, my dream of a submission protocol is somewhat more modest.
I wish a MUA (Mail User Agent) could be able to submit a mail in MIME
format without acting as a MTA (Mail Transfer Agent).
I told Ned in recent mail that I was about to give up hope
on this very concept. SMTP is an on-the-wire protocol. MIME is,
because of its being an IETF thing, also directed at IP, but is
all too often IMPLEMENTED OFF-the-wire. Think about it.
MIME works (IMHO) nicely when examined as "plain text
stored locally, then sent via mail" (whatever "mail" is).
Usually, but not always, this means the MIME object (a piece of
mail, or a note) will be carried over SMTP.
I've been making good use of 'sendmail -t' on UNIX.
There's an analog in many environments. The input to /usr/lib/sendmail
is NOT CRLF-delimited-lines, but NL-delimited-lines. Sendmail does
the translation (what there is of it) to SMTP's idea of plain text.
implications as all (client-server) MUA's currently are destined to use
SMTP to submit outbound messages. It has to know if the mailbox address
differs from the identity of the user account. It is difficult as an
administrator to keep large sites MUA configurations synchronised (mail
domain and formal mailbox names, for example).
When submitting mail is implemented by function calls
instead of as a pipeline, then you can deal with non-zero return codes.
But that loses simplicity. It might be reasonable to test for
"consumer terminated" (SIGPIPE) as a first crack at doing it right.
(though UNIX sendmail won't quit, it just eats the whole message and
queues it; failure is deferred, and you get mail back from the daemon
(gee thanks) rather than immediate notification)
Then too re-writing sendmail to terminate early in case
of error won't help gatewayed (non SMTP) mail.
-- Tomas
--
Rick Troth <troth(_at_)ua1vm(_dot_)ua(_dot_)edu>, Houston, Texas, USA
http://ua1vm.ua.edu/~troth/
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