Under members you manage all registered and invited users on the platform.
If email verification is mandatory (see flag in 'settings' - 'general settings') the user must click on the link received in the verification email to complete the registration process.
To obtain the list of all users who have not completed the verification process, simply click on the TO BE VERIFIED button at the top of the list of users belonging to a group, next to the INVITED button.
NOTE: To verify a user manually, click on the name and then, in the tab containing the user's information, click on the VERIFY button.