I spent a day writing this when my Message Inbox was more than I could deal with. It takes messages from the private message XML ticker and turns them into messages an e-mail client can handle. It Works For Me now, and you're welcome to see if it works for you. You may also want to check out xunker's E2 Private Message to Email Gateway. E2Email works in a fetchmail-like fashion, grabbing your messages from the server and then delivering them locally. In contrast, xunker's gateway makes your Message Inbox accessible through a POP server.
E2Email is available under the BSD license and may currently be obtained from http://twistedmatrix.com/users/acapnotic/wares/code/E2Email/
Sending messages is what you can't do with this. :-( That would require two things:
- Interfacing with a Mail Transport Agent, getting it to intercept messages bound for e2 and passing them off to web-thingie. I don't currently know any MTA hooks well enough to do this.
- Having a server so configured available to send messages through. Generally speaking, it's much harder to obtain permission to play with a mail server configuration than it is to feed messages to an e-mail client. And riskier to do so too, if the server handles other traffic.