Function draft_envelope 

pub fn draft_envelope(text: &str, path: &Path) -> Envelope

A draft seen as a message, so hook patterns (~t, ~c, ~s, ~f, …) can be matched against outgoing mail the way mutt matches fcc-hook. path is where the body lives, so ~b and ~h still have something to read; the date is now, since the draft has no Date header yet. Bcc joins the Cc addresses, so a hook on ~c sees a blind recipient too.