Reject Posts From Non-members
This setting indicates that people who are not members of this mailing list will be allowed to post.
The default setting is "Yes," which means that if someone tries to contribute a message to this mailing list and their name or email address is not listed as a member of the list, their message will automatically be rejected.
A setting of "No" means that the person's contribution will not be rejected. However, if the list is moderated in some way (either full or number moderation) their message will require moderator approval. For example, if your list is set to number moderate, so that new members need their first message approved, any message coming from a non-member will be treated as if a new member posted it and will require moderator approval.
Allowing non-members to post and not having moderation means that anyone can send email to your list address, and it will be distributed to your members.
NOTE If Reject posts from non-members is set to Yes, and a non-member attempts to post a message, the post is not accepted and ListManager does not send a return message stating that the post failed. This is done in order to prevent responses to potential spam.
Security of Member List
By default, the listing of members of a mailing list is considered confidential and is only available to the list administrator. This option also allows you to make the listing of members available to members of the mailing list or to anyone. The "review" email command is used to obtain a member listing by email.