The email opt-in must be a clear and affirmative action.
The opt-in must be recorded in your database so that you can prove that you have actually received permission from the person concerned.
The opt-in must be separate from other conditions and may not be a condition for delivering a product or service. "When you accept the general terms and conditions you will automatically be registered for our newsletter'' is therefore prohibited.
It is forbidden to tick the opt-in checkbox automatically. This is called 'Privacy by default'.
You need separate opt-ins if you use the data in different ways, or when you use the same data for different purposes. This is also called 'goal-binding'.
Recipients have the right to withdraw the opt-in. You must clearly tell the recipient how they can unsubscribe. This can be included in a 'Privacy Statement.'