Implement un/serialization
JSON won't really work here, since we need to recreate buffers in a sane way. Other formats, like creationix/msgpack-js might work though.
Couldn't serialization just work on Envelope objects (or Envelope-like objects, that is JSON + buffers)?
So that this would be an identify function: X => serialize(new Envelope(X)) (approximately). The consumer would be responsible for putting buffers in their JSON tree.
Personally I really like the structure of Envelope objects, it's easy and understandable, so if I could just serialize that object into an e-mail that'd mean a lot!
Oh, I see my idea already has an issue: https://github.com/jhermsmeier/node-envelope/issues/10. Sorry for duplication :)