On Fri, Aug 21, 2026 at 16:57 +0200, Alejandro Colomar via Mutt-dev wrote:
When I forward a message, I want to have it threaded under the original
mail. For that, I manually add either an In-Reply-To or a References
(depending on my mood that day, I guess) to have it threaded by mutt(1).
I often forget to do this, so it would be nice if mutt(1) would do it
automatically.
I think Mutt should not do that, because a forwarded message is not a
reply. Those two message types are used for different purposes.
Conflating them would cause confusion and frustration.
Alejandro claims that RFC 5322 justifies this. He said:
RFC5322 says that reply messages SHOULD have "In-Reply-To:" and
"References:" fields as appropriate.
However, it doesn't anywhere say that other messages shouldn't have
them. Thus, my proposed extension would be conforming (not required,
not even suggested, but technically conforming).
Anything not specifically forbidden is fine? No.
I own a car; the manufacturer doesn't specifically forbid me to drive
it into a river. Does that mean I should?
The proposed change is a misuse of those headers. I suppose RFC 5322
doesn't specifically forbid it because the authors didn't think they
had to spell it out.
