On 2019-09-06 10:50, Kevin J. McCarthy wrote:
Both "new" and "old" are "unread". "read" means neither new nor old.
That sounds familiar. I think that goes back about 40 years, long before Mutt, to how spooling of incoming messages was implemented, and the introduction of the non-standard header Status:.
Messages that had never seen by a mail reader were "new". Those that had been seen by a mail reader but not by the user were "old". Those seen by the user were "read".
Does Mutt store this as a single state with three possible values? Clearly there's some logic on top of that. Also clearly, this is burdened with 40 years of compatibility.