These owners will not receive error messages. You are encouraged to specify a backup list owner. If you'd like more than two, additional owners can be added once list is created. Private list subscriptions must be added by the list owner. This is an appropriate setting for an announcements list.
List is for discussion among subscribers.
Allowing anyone to post may invite off-topic postings such as advertisements or chain letters. Unless the operation of your list requires the posting of attachments, this is the recommended setting. This is an appropriate setting for an announcements list. Use to promote general discussion among subscribers. Use for announcement lists where owner wants to receive replies, or to reduce replies on discussion lists.