flectra/addons/website_mass_mailing/views/unsubscribe_templates.xml

<?xml version="1.0" encoding="utf-8"?>
<flectra>
    <template id="unsubscribe">
        <div class="container o_unsubscribe_form">
            <div class="row">
                <form action="/mail/mailing/unsubscribe" method="POST" id="unsubscribe_form">
                    <input type="hidden" name="csrf_token" t-att-value="request.csrf_token()"/>
                    <input type="hidden" name="email" t-att-value="email"/>
                    <input type="hidden" name="mailing_id" t-att-value="mailing_id"/>

                    <div class="col-md-6 col-md-offset-3">

                        <h1 class="page-header">Mailing Subscriptions</h1>

                        <t t-if="contacts">
                            <div class="alert alert-info text-center">
                                <p>Choose your mailing subscriptions.</p>
                            </div>

                            <ul class="list-group">
                                <t t-foreach="contacts" t-as="contact">
                                    <li class="list-group-item">
                                        <input type="checkbox" class="mail_list_checkbox" name="contact_ids"
                                            t-att-value="contact['id']" t-att-checked="'checked' if contact['opt_out'] == False else None"/>
                                        <t t-foreach="contact.list_ids" t-as="contact_list">
                                            <t t-esc="contact_list.name"/> 
                                        </t>
                                    </li>
                                </t>
                            </ul>

                            <div class="text-center mb16">
                                <input type="submit" id="send_form" class="btn btn-primary" value="Update my subscriptions"/>
                            </div>
                        </t>

                        <t t-if="contacts == False">
                            <div class="alert alert-info text-center">
                                <p>You are not subscribed to any of our mailing list.</p>
                            </div>
                        </t>
                    </div>
                </form>
            </div>
        </div>
    </template>

    <template id="unsubscribed">
        <div class="container mt8">
            <div class="row">
                <div class="col-md-6 col-md-offset-3">
                    <h1 class="page-header">Mailing Subscriptions</h1>

                    <div class="alert alert-success text-center">
                        <p>You have been successfully <strong>unsubscribed</strong>!</p>
                    </div>
                </div>
            </div>
        </div>
    </template>

    <template id="page_unsubscribe" name="Unsubscribe">
        <t t-call="website.layout">
            <t t-call="website_mass_mailing.unsubscribe"/>
        </t>
    </template>

    <template id="page_unsubscribed" name="Unsubscribed">
        <t t-call="website.layout">
            <t t-call="website_mass_mailing.unsubscribed"/>
        </t>
    </template>
</flectra>