Similarly, I think most people are unconsciously aware of technology used over the decades in recording studios. As recording equipment has evolved over time, periods of time have come to have their own sound that I think we easily pick up on. I'm not talking about the instruments, but the electronics that the signals pass through on the way to making an album. A solo guitar record from the 60s *sounds* different from one made in the 80s or 00s. (Maybe that's a weak example-- the more complex the recording, the more obvious the imprint of the gear, probably.) Its the microphones, the mixing board, the compressors, the mastering process, etc. All of it has, and will, change over time. I'm not a scientist but I think alot of people can tell in their gut what decade a song is from, even if they've never heard it before. And I think its really interesting that these differences can come through on even the crappiest of stereo systems.

Exaclty!

Deciding *what* email you want to save/track and *why* you want to save/track it will lead you toward the how. Is there a need to reference the whole archive of past email? Or delegate these emails to various members for follow up? (Probably both, I'd guess.)

I think no matter what is used, things will turn into a mess again without some sort of discipline and authority (even if the authority is just a set of rules for the users to follow). Along these lines, someone in the group should have admin duty and be able to clean up or veto tags or folders made by other group members.

By the way -- I'd consider smart folders (aka saved searches) because they are not mutually exclusive like folders, and they update themselves as new mail comes in. They can even work on top of or in spite of other folder structure. The drawback is that they depend on message content. I.e., if a message does not match the criteria, it is not included. Also, they require more work than tags, which gets back to the idea of an admin/janitor who specializes in this.