User can unsubscribe from newsletter subscriber list from front-end by submitting email id. You can add link in newsletter message , by clicking in this link the customer have page with input form , allows customer to unsubscribe newsletter subscription directly by submitting email id through front-end. So he does not need to depend on admin. The unsubscription form page takes email id as input & unsubscribe the user if already registered for subscription.

• unsubscribe from newsletter list form
• send message unsubscribe confirmation