For better or worse, we've got a perfectly good, standard, way of doing that when the list is to be treated as the sender. That would be to ask developers of list software to use Resent-From.
ARC adds a cryptographic chain of signatures adopted from DKIM. I suppose you could use an extended version of Resent-From but it'd amount to the same thing.
Regards, John Levine, johnl@xxxxxxxxx, Taughannock Networks, Trumansburg NY Please consider the environment before reading this e-mail.