Re: Intent to revive "expires" header from draft-ietf-mailext-new-fields-15

Hi,

  
> So, what would you want the recipient MUA to do with these. The
> consensus seems to be that they should still receive them - so what
> difference does the 'expires' make? Automatically moving them into
> another folder when they arrive is nearly the same as automatically
> deleting them as far as many users goes! Showing them in grey or
> another colour doesn't stop people having to read them to see if
> they've missed something important.

Showing them in grey (or something similar) should be the
default behavior, but a reasonable MUA would allow a user
like me to let the emails automatically be deleted (or
moved to a folder, which, as you correctly state, is
quite similar to deletion). That should be an option
for people who want it, and I guess it would.


> "confirm your subscription to list X in the next 3 days" is still
> important if you receive it 4 days later. Now you know you need to try
> again to get onto the list.

Let's apply the semantics that we all more or less seem
to agree on here, and which Keith Moore just beautifully
phrased as:

"The sender believes this message will be irrelevant 
after the indicated date/time."

Then this is a bad example, as the message does not become
irrelevant after the next 3 days. It would be foolish for
the sender to believe that it does become irrelevant (and
foolish to configure a mailing list system to act that way).


> "I'm out of the office until ..." may be important, you may have been
> bad-mouthing a contact because they hadn't replied to you earlier, and
> now you'll know why

You have no right to bad-mouth a contact when you configure
your MUA to automatically delete expired emails. Given our
previous discussion, it must have been your intention to
configure your MUA in this way, so you understand the option
well enough to know better than to bad-mouth the person
just for using an expiry date.


> "special offer valid until ..." may still be important from the
> sender's point of view as a "buy our wonderful flying car for only
> $15,000 before 30th July, look how amazing it is..." is still a good
> advertisement if it's received on the 1st August, and the recipient
> may still want it even though the special offer has expired.

No, this is truly outdated information - by making use
of the expiry date at the receiving end, you either
declare a general interest in such things that have
become irrelevant from the sender's point of view,
or not, depending on how many emails you get, how
much time you have, and what kind of person you are.

Take talk announcements and CFP's, which I used as an
example before: of course you can construct a case
where a person would be interested in such emails even
when they're over. Say you're the institute head here,
interested in how many and what kind of talks happen -
of course you also want to be informed when the talks
are in the past, but most people won't.

If the current date would be incorporated in filters
of MUAs as something to check against, such a person
could be properly served - and adding this function
would seem to be the most obvious and easy way to
deal with the expiry date in a MUA in my opinion.


> > Good examples apparently require some kind of mailbot
> > on the sender's side.  It is less useful for ordinary
> > (sending) MUAs, e.g., "happy birthday" with Expires: 
> > makes no sense, or does it ?
> >   
> No it doesn't. If 'happy birthday' arrived late, you'd still want the
> recipient to know you'd thought of them, so in that case 'better late
> than never' applies.

Right, that's just a bad example.


> 'expires' only makes sense (IMV) if it would reduce the mail to be
> read by the recipient by getting rid of stuff that's absolutely no use
> any more. In that case, it may as well be deleted automatically - but
> no one wants that. My problem is that I can't think of anything which
> is *absolutely* no use after a certain date (which *would* have been
> of some use before that date). So, you'd still need to read expired
> mail to see if it's of some use to you - in which case what's the
> point?

People are different. I'd be more than happy to let my MUA
even silently delete past:

* talk announcements
* CFPs
* special offers
* "out of the office messages"

Cheers,
Michael