Thanks, but.. That's not quite what I had in mind. For one, somedb-only (sqlite or anything else) is usually not enough. I would hesitate to introduce a system that just supports mysql when everything else is using postgresql for me, for example. And on top of that, this schema is .. limited. My dspam setup learns and can do that for each and every user (though system wide training seems to be the norm, as far as I can tell). This is really just a storage engine as far as I can tell and not really comparable.

That said: I guess I would give rspam a try if I saw a lot of positive reviews/reports. It's just that it certainly doesn't do the same thing as dspam. It's quite a different animal.