aldryn_config.py

from aldryn_client import forms


class Form(forms.BaseForm):

    show_all_recipients = forms.CheckboxField(
        'Show all users as selectable e-mail recipients (not only admins)', required=False, initial=True)

    def to_settings(self, data, settings):
        settings['ALDRYN_FORMS_SHOW_ALL_RECIPIENTS'] = data['show_all_recipients']
        return settings