I apologize for responding a YEAR LATE!
Email unsubscribe buttons typically aren't the most reliable... Instead, to unsubscribe from Codecademy emails, enter your Codecademy "My Account" tab, found by clicking your avatar in the top left corner while on the Codecademy website. From there, select Mail Settings, and check the box next to "Don't send me any emails".
This should unsubscribe you, that is if you're still receiving them after this long.