This setting indicates that people who are not members of
this mailing list will be allowed to post.
The default setting is
"NO" that means that if someone tries to contribute a message to this
mailing list, and their email address is not listed as a member of the list,
their message will automatically be rejected.
A setting of "YES" 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 be
put of for 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.
Please note that 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.