Lists for open discussion should require such hoops for participation,
esp. when there are plenty of reasonable, sufficiently correlated
identifiers than "not a list member" to identify spam.
assuming you meant "should not require" I'm very much in agreement.
especially when it's trivial to fix things so that the process used
by a moderator to approve a message also adds the sender of that
message to the "allowed posters" list.
Keith