I want a file store which I can email stuff into. The subject lines of emails would be broken into tags, and attachments associated with the tags. I could get RSS feeds of specific tags - e.g. so I can email a file in, tag it "mobile" and "ui", and a colleague can subscribe to all new files tagged "ui" by RSS.

Does such a beast exist? Ideally open source software we can host at FPHQ rather than third-party hosted.