Adding the Email Opt-In Requirement for your Account

To specify that only contacts who have been marked as authorized to receive communications will receive emails you send:

1. Navigate to Settings > Company Profile.
2. In the Opt-In Authorization field, enable the Opt-In Authorization is required for a contact to be sent an email setting.
3. [Optional] Enable the Add Any Unsubscribes to Global Suppression List setting to ensure you keep a record of contacts who opt out of communications. 
4. [Optional] Update the template for the opt-in confirmation email with personalized information at Opt-in Authorization > Confirmation Email. For more information, see Personalize Your Opt-In Confirmation Emails.
5. Click Save to update the Company Profile. You will be prompted for opt-in confirmation when importing a list or creating an individual contact. 

If you leave the Opt-In Authorization setting disabled, you state that authorization is implied. For more information, see Company Profile.