On 2/28/2011 7:20 PM, John Levine wrote:
I do like the idea with respect to alerts; if email programs (especially
those on smart phones) would know to avoid alerting you of unread +
expired messages, that could be quite beneficial. Especially if I could
set expiration times with thunderbird filters.
If people keep at it, they may yet reinvent RSS which, I note, T'bird
supports reasonably well.
The main appeal of Expires: is to spammers and near-spammers, who hope
they can make the mail go away before people complain about it. As I
pointed out to Ken Magill, usenet has had an Expires: header for
decades, the design of usenet makes it cheap to implement, and it has
never been useful in practice.
Well for starters folks, most of what has been discussed here is a
pile of baloney.
For starters, there IS ALREADY AN EXPIRATION HEADER for e-mail. It was
first defined in RFC 1327, it is:
Expiry Date Indication
Supported as new RFC 822 header (Expiry-Date:). In general,
no automatic action can be expected.
This header definition is also expanded on in RFC 2076.
However I will point out that RFC 2076 discusses this entire expiration
thing. RFC 2076 permits use of many Usenet News article headers in
e-mail messages with the caveat that just because it's permitted does
not mean that MUAs are required to support it.
Because Usenet uses "Expires:" as a header, RFC 2076 basically strongly
suggests that if your going to use an expiration header in an e-mail
message, that you use the Usenet one, not the X.400 one (unless your
communicating with an X.400 system of course) from RFC 1327.
As for spammers wanting an expires header to make spam go away before
you can complain about it, this is a joke, right?
If MUA's supported an Expires header than us administrators could
configure our spamfilters to put a 5 day expiration header in anything
we get that we think is spam. That would HELP us. It is the last thing
a spammer wants.
Be serious. Any MUA that implements an Expires: header would do the
same thing that MUA's do with X-Confirm-Reading-To:
Disposition-Notification-To: or Return-Receipt-To: headers - when the
MUA encounters
the header it queries the user if it wants the user to act on it -
or it silently does it or ignores it, depending on the setting of
a checkbox in the MUA configuration. Implementing Expires: would be
no problem at all.
From a legal perspective I will point out that any e-mail you
receive is (at least in the US, but most other countries too)
considered copyrighted by the sender. Under copyright law the
sender has the right to control expiration of content they create,
the movie houses are doing this with digital copies that are
time-limited and included with blue-ray disc purchases. Thus if
a corporation suddenly has e-mail disappearing from it's servers
due to expiration dates inserted by the e-mail creator they are
absolutely protected from a legal point of view - because of the
demands of copyright law.
If a court subpoenas from company X an e-mail that the sender
had copyrighted and forced to expire, then company X can merely
state that they don't have the e-mail because they were following
the demands of copyright law that says they must expire the e-mail
when the sender (copyright holder) wanted it to be expired. Legally
a company or individual cannot be prosecuted for following the law,
so no matter how much the court might have really, really wanted
them to retain a copy of the e-mail, they cannot punish them for
failing to comply with the subpoena.
Where it would get very interesting is that many times e-mails
are cut and pasted together. In that case the actual copyright
ownership is very murky. Normally you would argue that the
last person to send the message is the copyright holder. For
example in this particular post I am including copyrighted material
from John Levine (the first part of the posting) BUT because I am doing
it under the doctrine of Fair Use, the ENTIRE post, including his parts,
is under MY copyright. If he were to sue me for infringement
if a judge sided with my interpretation of it as Fair Use then he
would lose. Thus, if I put an expiration date on this, even if
he objects to expiration dates, he is screwed. But if the judge sided
with HIS interpretation, then -I- would be screwed. In this kind
of case, a corporation basically is in a dammed if they do, dammed
if they don't situation, so basically whether or not to honor Expires:
is going to end up being a decision that most corporations would
probably take the approach that in most cases they are better off with
LESS of an e-mail trail so if they have any excuse to be able to
legally "shred" e-mail early, then they would take it.
Ted
