An integration with the WordPress Newsletter plugin has been made into the Profile Builder plugin to capture subscribers through registration forms.
When you manage fields in the Profile Builder plugin on your WordPress website, a “Newsletters” field is available to add a subscribe checkbox to your registration form.
You can configure this “Newsletters” field by specifying a custom title, auto checking it, adding a custom checkbox label, choosing the list(s) that users will be subscribed to in the WordPress Newsletter plugin.
As users registered on the registration form with the subscribe checkbox checked, they will be subscribed as Newsletter subscribers.