re: Some thoughts on search engines and Google in particular
I guess you could have a duplicate of every message, stored where Google can see it, but that sounds expensive in disc space...
Nonetheless, because it would be a backup list, you wouldn't need your local database to be burdened by searching through all that, but if someone picks up on one of those stored messages, the links from it would re-enter the zone in the "normal" fashion.
As I recall, there are ways to get Google spiders to go to particular locations that aren't visible to the casual browser. In this way you can lead it to your archive.