Abandoning the concept of groups as a storage medium?

[Jan Rychter <jan@rychter.com>]

Here's some context: I've been a Gnus user for the last 13 years or
so. I use nnml as my mail backend. I used Linux for ten years, then
moved over to Mac OS X. You might say I'm not exactly a newbie.

I've always been trying to make my mail searchable. I tried namazu in
the past, but it didn't work well for my volume of mail. I hacked a
plugin for Spotlight that indexes an NNML spool. It works, but needs
polishing, and is only useful for finding a single E-mail message.

Then I discovered mairix and nnmairix. They are close to what I need,
but there is the issue of flag propagation, which nnmairix doesn't do
for an NNML spool.

Which brings me to my main point. I believe the notion of splitting all
mail into groups is fundamentally flawed. Yes, it makes sense for
mailing lists, but it doesn't for pretty much anything else. I would
much rather assign tags and have a good search interface. I want to
access my mail in a multitude of ways, searching by date, sender, tags,
and picking out entire conversations (threads). I want to be able to set
flags and tags on *any* E-mail message *anywhere*, not just in the "real
group it belongs to". I don't want my "groups" to have anything to do
with the way my messages are stored. E-mail should be stored in a
key/value store with metadata copied and indexed separately.

The problem I see with Gnus is that it is designed around a central
concept of a mail backend which exposes groups. The registry, if I
understand correctly, is a workaround for some of the problems people
encountered with this approach.

Is there any way to achieve what I want with Gnus? Is anybody working on
something of the kind? What would be the possible approaches?

--J.