Re: Scope for self-destructing email?

[[e-mail]]

> In article <[e-mail]> you write:
> >This is an interesting idea.  For those of us who deal with many emails,
> >(particularly upon return from vacation), not having to deal with lunch plans
> >that have expired would in fact be nice.

> See RFC 2156 and RFC 4021, section 2.1.50.  To me the interesting
> question is why, since we've had Expires: for 20 years, nobody uses it
> outside of netnews.

More like 30+ years. See RFC 841, section 3.2.5, also X.400-1984.

> > That's a job for good-old-Usenet Supersedes:,
> >but that's one email overcoming another, and the whole thing needs
> >some cryptographic support.  Note that a merkle hash (a la s/key) would
> >probably suffice.

> Seems like overkill.  How about you pay attention to the Supersedes:
> (see RFC 2156 and RFC 4021, section 2.1.46) if old and new messages
> both have DKIM signatures from the same domain?  Same question about
> why after 20 years nobody uses it outside of netnews.

And if you want to explore the cryprographic side of this, there's an
extensive literature. A good place to start is Radia Perlman's "The Ephemerizer
- Making Data Disappear".

				Ned