>>>>> "SJ" == Simon Josefsson <jas@extundo.com> writes:

    SJ> Joseph Barillari <jbarilla@princeton.edu> writes:
    >> I was surprised that Gnus didn't support Delivery Status
    >> Notification. I've patched OGnus 0.05 message.el to handle it;
    >> the patch is attached.

    SJ> Thanks.

    SJ> It looks specific to sendmail.  Maybe renaming the variables
    SJ> to `message-sendmail-use-dsn-*'?  Alternatively, implementing
    SJ> it for non-sendmail methods as well (smtpmail, qmail, ...), of
    SJ> course.

qmail doesn't support DSN [0]. Neither does Exim. As for the rest, I
don't know.

    >> Given that DSN support requires only a few lines of code, was
    >> there a philosophical reason for its exclusion?

    SJ> I think it has been discussed a few times here before (see the
    SJ> archives).  If it is disabled by default, I don't see any harm
    SJ> in supporting it.

    SJ> Would it be useful to have toolbar buttons and message mode
    SJ> key bindings for requesting DSN on a message?  I'm not sure
    SJ> you'd want to use DSN on all messages.

Not a bad idea, but I use it on all messages, with a procmail rule to
save the receipts in an mbox if I should ever need them. A nifty hack
would be to have Gnus process the incoming DSN messages, and insert a
header into the corresponding sent messages to indicate their final
disposition. It could (perhaps) tick messages that were delayed or
failed.

But if Bernstein is correct in asserting [0] that `DSN is obsolete',
implementing such a feature may be a waste of time.

    SJ> Do you want to write documentation for it as well
    SJ> (message.texi)?  Have you signed FSF papers?

I think this falls into the `too trivial to need copyright
reassignment' category. But if it's necessary, sure.

Speaking of which, I just re-read the patch and realized that it
patches the code relative to one of my earlier revisions, rather than
relative to a vanilla version of Gnus. I've attached a fresh patch
against 0.06 from CVS. Please disregard the last one.

As for the documentation, the following should suffice:

    Delivery Status Notification (see
    http://www.sendmail.org/~ca/email/dsn.html) is a means by which
    MTAs can report the final disposition of a message. Support for
    DSN varies: recent versions of Sendmail may have it enabled, but
    Exim and qmail do not support it. DSN `success' status messages
    will be returned by the last mail server in the relay sequence
    capable of DSN. Microsoft Exchange generates DSN `success'
    messages. Sendmail can be configured to do so.

    If the variable `message-use-dsn-failure' is non-nil, Gnus will
    ask the MTA to ask for DSN status messages if delivery
    fails. Likewise for delivery delays, with `message-use-dsn-delay',
    and successful delivery, with `message-use-dsn-success'.

--Joe

[0] <http://www.sendmail.org/~ca/email/qm-sm.html>

Corrected patch follows: