> All of these "attempted posts" (as opposed to bounces) must be forwarded
> to the list owner for determination, because it's possible that these were
> real posting attempts that only _looked_ like they might be misdirected
> bounces.
>
> Francoise

It makes sense, mostly.  However, it's not explained in the documentation.
The List Owner's Manual leads one to believe that all of those annoying
error messages will stop, but they don't.