You can use member moderation to approve new members before they join your Ning Network by requiring them to apply for membership. To turn on member moderation, go to the Members Management Icon and click on the “Settings” tab. Check the box next to “Approve new members before they can join.”
When a new member wants to join your Ning Network, they will create a profile and then be placed in a “pending approval” status. You and your administrators will receive an email notification that you have a new member to approve.
Click the link in this notification email and you’ll be taken to a page listing all of the members currently awaiting approval on your Ning Network. Click the “View Page” link to check out the profile they’ve filled out to join. Here, you can approve or decline your new applicants. Once you have approved a new member on your Ning Network, this member will automatically be notified by email that their membership has been approved. Applicants whose membership request is declined will not receive an email.