When a user registers without invitation (self-registration), the email address that has been used must be confirmed.
In order to do this, users must go to their inbox and click on CONFIRM EMAIL ADDRESS. The service provider (Quote Manager/admin to be exact) receives a notification that the user has registered and will verify this registration as soon as possible. If the service provider has activated automatic registration, verification is not necessary but confirming the email address is! Learn more about automatic registration here.
NOTE: when the User Status = ConfirmEmail, no action is needed from the admin. Confirming that the email address is valid is something the end-user does by clicking on the link they should have received if the email address was indeed correct.