I've been experimenting with Zoe, an e-mail relevance engine. It's hard to describe exactly what it does - it reads your e-mail and discerns patterns. It will check your mail via POP/IMAP and keep histories. I ran all my mail that I still have maintained on disk somewhere through it, 25,000 messages going back to 1995. With one command I can search through all of that via a web based client, navigate through recipient, follow threads (with the repeated, quoted material eliminated !) and other fun value added things. I'm thinking that I will like this.