Re: Why article numbers?

[Michael Shields <shields@msrl.com>]

In article <m3lm08xa74.fsf@multivac.cwru.edu>,
prj@po.cwru.edu (Paul Jarc) wrote:
> I think I should point out that Kai and I seem to be advocating
> slightly different things.  Kai's suggestion, AIUI, is to use
> Message-ID header fields as article IDs everywhere.

One wrinkle with this is that it's possible for messages to have no
message-ID.  This never happens in news or with most MTAs, but it's
legal in mail.  One way it can happen is when using `G f' to read an
mbox-format archive that has incomplete headers.

It's also possible, and not uncommon, for the same mail message to be
delivered twice -- because you receive it both directly and via a
mailing list, or theoretically because an SMTP connection was dropped
after the "." but before the acknowledgment.

> My suggestion is
> to let backends decide how to identify articles, with the only
> requirement being that identifiers should be eq if they are supposed
> to identify the same article.  (This includes the possibility of
> symbols whose names are Message-IDs, but does not require that.)

That seems reasonable, especially sine it lets the conversion be done
one backend at a time, or not at all for some backends.

For mail with no message-ID, fake ones could be generated; I seem to
remember VM doing this (with "@toto.iv").  I'm not sure what is the
best way to handle duplicates.

Message-IDs are fine identifiers for news.
-- 
Shields.