I was reading that page and was just getting more and more confused and then eventually I realised it’s an alternative to IMAP. Pretty cool.

Please correct me if I’m wrong, but doesn’t this allow one to represent virtually any resource as a mail inbox/outbox with access through a generic mail app?

I’m working with a specialized healthcare company right now, and this looks like a way to represent patient treatments data as an intuitive timeline of messages. With a local offline cache in case of outages. Security of local workstations is a weak point of course, but when is it not…