Quoting Roberto Leibman (roberto@leibman.net):
We've had this discussion before. I remember good arguments pro and good arguments against. I think we decided that the list owner gets to decide, and the rest of us live with it.
Fortunately, mutt automatically ignores "munging", so it doesn't hurt me, either way. It hurts only the people who repeatedly get surprised by their very private side-discussions, that they intended to send off-list, getting forced into public.
Some things are matters of opinion, but this is not: IETF settled the notorious controversy 21 years ago, ruling in two RFCs that "munging" is inappropriate, and introducing the List-Post: header to designate to software the method for posting to a mailing list.
At that time, Neale Pickett explained briefly, in plain English, how the technical problem got resolved, and why it's a dead argument. Please see. http://marc.merlins.org/netrants/reply-to-still-harmful.html