Customize Your Unsubscribe Page
When your subscribers click the "Unsubscribe" link at the bottom of your newsletters, they will be directed to MailPoet's default Unsubscribe page. If you want to use a custom Unsubscribe page instead, here's how you can do it.
Go to your WordPress Dashboard > Pages > Add New:
You're going to create a new page to be your custom Unsubscribe page:
You can also add the shortcode [mailpoet_manage text="Manage your subscription"], in case the user had been accidentally unsubscribed, so they can manage their subscriptions.
After having your new page created and published, access MailPoet > Settings > Basics
On the Basics tab, go to the Unsubscribe page section and select the custom Unsubscribed page created from the drop-down menu:
You can click on Preview link to see what your custom Unsubscribe page will look like. Don't forget to save your settings when you finished editing.
And if you're using the shortcode, it should look like this: