Enable One-Click Unsubscribe for List Header

This step is required only if you want to implement the One-click Unsubscribe option. For details on how One-click Unsubscribe works, see How Email Compliance List Unsubscribe Header Works.

1. Navigate to Setup > Custom Settings.
2. Next to Email Editor Settings click Manage.
3. Click Edit.
4. Check the Include List-Unsubscribe-Post Headercheckbox.
5. Click Save.