By default after Membership registration will be automatically created and activated the Membership account for user. But on Profile Tab of Membership Settings you can find Registration Confirmation option. This feature allows you to enable Email Confirmation by user or Registration Confirmation by Membership Administrator.
Email confirmation – after registration user will receive the confirmation message on his/her email address. To activate the account, he/she will need to click the link inside the confirmation letter to confirm the email address.
Administrator confirmation – in this case after the new user registration – administrator will receive Pending Review Email. In this letter administrator can check the information about new user and make the decision – approve or reject the account. To make decision – go to Users page in WordPress menu -> find the user profile -> click Edit -> choose the Status for account – Active or Rejected. Besides here you can select another statuses – Deleted, Disabled, Pending Review. After the administrator will choose the status – user will receive the email about the admin decision.