diff --git a/mass_mailing_custom_unsubscribe_event/README.rst b/mass_mailing_custom_unsubscribe_event/README.rst
new file mode 100644
index 000000000..10ecb4314
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/README.rst
@@ -0,0 +1,91 @@
+=============================================
+Allow to unsubscribe discretely from an event
+=============================================
+
+.. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+   !! This file is generated by oca-gen-addon-readme !!
+   !! changes will be overwritten.                   !!
+   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+.. |badge1| image:: https://img.shields.io/badge/maturity-Beta-yellow.png
+    :target: https://odoo-community.org/page/development-status
+    :alt: Beta
+.. |badge2| image:: https://img.shields.io/badge/licence-AGPL--3-blue.png
+    :target: http://www.gnu.org/licenses/agpl-3.0-standalone.html
+    :alt: License: AGPL-3
+.. |badge3| image:: https://img.shields.io/badge/github-OCA%2Fsocial-lightgray.png?logo=github
+    :target: https://github.com/OCA/social/tree/12.0/mass_mailing_custom_unsubscribe_event
+    :alt: OCA/social
+.. |badge4| image:: https://img.shields.io/badge/weblate-Translate%20me-F47D42.png
+    :target: https://translation.odoo-community.org/projects/social-12-0/social-12-0-mass_mailing_custom_unsubscribe_event
+    :alt: Translate me on Weblate
+.. |badge5| image:: https://img.shields.io/badge/runbot-Try%20me-875A7B.png
+    :target: https://runbot.odoo-community.org/runbot/205/12.0
+    :alt: Try me on Runbot
+
+|badge1| |badge2| |badge3| |badge4| |badge5| 
+
+This addon extends the unsubscription process for allowing to unsubscribe
+only for an event.
+
+Standard process includes the mail in the general blacklist instead, which
+can be very unconvenient.
+
+**Table of contents**
+
+.. contents::
+   :local:
+
+Usage
+=====
+
+#. Go to *Email Marketing > Mailings > Create*.
+#. Select "Event Registration" in *Recipients* field.
+#. Edit your mass mailing at wish, but remember to add a snippet from
+   *Footers*, so people have an *Unsubscribe* link.
+#. Send it.
+#. If somebody gets unsubscribed, it will get unsubscribed only for that
+   event, but including that mail in other event, the registree will still
+   receive mailings.
+
+Bug Tracker
+===========
+
+Bugs are tracked on `GitHub Issues <https://github.com/OCA/social/issues>`_.
+In case of trouble, please check there if your issue has already been reported.
+If you spotted it first, help us smashing it by providing a detailed and welcomed
+`feedback <https://github.com/OCA/social/issues/new?body=module:%20mass_mailing_custom_unsubscribe_event%0Aversion:%2012.0%0A%0A**Steps%20to%20reproduce**%0A-%20...%0A%0A**Current%20behavior**%0A%0A**Expected%20behavior**>`_.
+
+Do not contact contributors directly about support or help with technical issues.
+
+Credits
+=======
+
+Authors
+~~~~~~~
+
+* Tecnativa
+
+Contributors
+~~~~~~~~~~~~
+
+* `Tecnativa <https://www.tecnativa.com>`_:
+
+  * Pedro M. Baeza
+
+Maintainers
+~~~~~~~~~~~
+
+This module is maintained by the OCA.
+
+.. image:: https://odoo-community.org/logo.png
+   :alt: Odoo Community Association
+   :target: https://odoo-community.org
+
+OCA, or the Odoo Community Association, is a nonprofit organization whose
+mission is to support the collaborative development of Odoo features and
+promote its widespread use.
+
+This module is part of the `OCA/social <https://github.com/OCA/social/tree/12.0/mass_mailing_custom_unsubscribe_event>`_ project on GitHub.
+
+You are welcome to contribute. To learn how please visit https://odoo-community.org/page/Contribute.
diff --git a/mass_mailing_custom_unsubscribe_event/__init__.py b/mass_mailing_custom_unsubscribe_event/__init__.py
new file mode 100644
index 000000000..69f7babdf
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/__init__.py
@@ -0,0 +1,3 @@
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from . import models
diff --git a/mass_mailing_custom_unsubscribe_event/__manifest__.py b/mass_mailing_custom_unsubscribe_event/__manifest__.py
new file mode 100644
index 000000000..c36e0dd93
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/__manifest__.py
@@ -0,0 +1,16 @@
+# Copyright 2020 Tecnativa - Pedro M. Baeza
+# Copyright 2020 Tecnativa - João Marques
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+{
+    "name": "Allow to unsubscribe discretely from an event",
+    "category": "Marketing",
+    "version": "13.0.1.0.0",
+    "depends": ["event", "mass_mailing_custom_unsubscribe"],
+    "author": "Tecnativa, Odoo Community Association (OCA)",
+    "website": "https://github.com/OCA/social",
+    "data": ["views/event_registration_views.xml"],
+    "demo": ["demo/assets.xml"],
+    "license": "AGPL-3",
+    "installable": True,
+    "auto_install": True,
+}
diff --git a/mass_mailing_custom_unsubscribe_event/demo/assets.xml b/mass_mailing_custom_unsubscribe_event/demo/assets.xml
new file mode 100644
index 000000000..eefa8fa52
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/demo/assets.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2020 Tecnativa - João Marques
+     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). -->
+
+<odoo>
+
+<template id="assets_frontend_demo"
+          inherit_id="web.assets_frontend">
+    <xpath expr=".">
+        <script type="text/javascript"
+                src="/mass_mailing_custom_unsubscribe_event/static/src/js/tour.js"/>
+    </xpath>
+</template>
+
+</odoo>
diff --git a/mass_mailing_custom_unsubscribe_event/i18n/mass_mailing_custom_unsubscribe_event.pot b/mass_mailing_custom_unsubscribe_event/i18n/mass_mailing_custom_unsubscribe_event.pot
new file mode 100644
index 000000000..829e503c2
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/i18n/mass_mailing_custom_unsubscribe_event.pot
@@ -0,0 +1,30 @@
+# Translation of Odoo Server.
+# This file contains the translation of the following modules:
+#	* mass_mailing_custom_unsubscribe_event
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: Odoo Server 12.0\n"
+"Report-Msgid-Bugs-To: \n"
+"Last-Translator: <>\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: \n"
+"Plural-Forms: \n"
+
+#. module: mass_mailing_custom_unsubscribe_event
+#: model:ir.model,name:mass_mailing_custom_unsubscribe_event.model_event_registration
+msgid "Event Registration"
+msgstr ""
+
+#. module: mass_mailing_custom_unsubscribe_event
+#: model:ir.model.fields,help:mass_mailing_custom_unsubscribe_event.field_event_registration__opt_out
+msgid "If opt-out is checked, this registree has refused to receive emails for mass mailing and marketing campaign."
+msgstr ""
+
+#. module: mass_mailing_custom_unsubscribe_event
+#: model:ir.model.fields,field_description:mass_mailing_custom_unsubscribe_event.field_event_registration__opt_out
+msgid "Opt-Out"
+msgstr ""
+
diff --git a/mass_mailing_custom_unsubscribe_event/models/__init__.py b/mass_mailing_custom_unsubscribe_event/models/__init__.py
new file mode 100644
index 000000000..950934286
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/models/__init__.py
@@ -0,0 +1,3 @@
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from . import event_registration
diff --git a/mass_mailing_custom_unsubscribe_event/models/event_registration.py b/mass_mailing_custom_unsubscribe_event/models/event_registration.py
new file mode 100644
index 000000000..80afcd8ff
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/models/event_registration.py
@@ -0,0 +1,15 @@
+# Copyright 2020 Tecnativa - Pedro M. Baeza
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from odoo import fields, models
+
+
+class EventRegistration(models.Model):
+    _inherit = "event.registration"
+
+    opt_out = fields.Boolean(
+        string="Opt-Out",
+        help="If opt-out is checked, this registree has refused to receive "
+        "emails for mass mailing and marketing campaign.",
+    )
+    # No need of email field, as it already exists
diff --git a/mass_mailing_custom_unsubscribe_event/readme/CONTRIBUTORS.rst b/mass_mailing_custom_unsubscribe_event/readme/CONTRIBUTORS.rst
new file mode 100644
index 000000000..769b9f27a
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/readme/CONTRIBUTORS.rst
@@ -0,0 +1,4 @@
+* `Tecnativa <https://www.tecnativa.com>`_:
+
+  * Pedro M. Baeza
+  * João Marques
diff --git a/mass_mailing_custom_unsubscribe_event/readme/DESCRIPTION.rst b/mass_mailing_custom_unsubscribe_event/readme/DESCRIPTION.rst
new file mode 100644
index 000000000..307efe31c
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/readme/DESCRIPTION.rst
@@ -0,0 +1,5 @@
+This addon extends the unsubscription process for allowing to unsubscribe
+only for an event.
+
+Standard process includes the mail in the general blacklist instead, which
+can be very unconvenient.
diff --git a/mass_mailing_custom_unsubscribe_event/readme/USAGE.rst b/mass_mailing_custom_unsubscribe_event/readme/USAGE.rst
new file mode 100644
index 000000000..552d294ec
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/readme/USAGE.rst
@@ -0,0 +1,8 @@
+#. Go to *Email Marketing > Mailings > Create*.
+#. Select "Event Registration" in *Recipients* field.
+#. Edit your mass mailing at wish, but remember to add a snippet from
+   *Footers*, so people have an *Unsubscribe* link.
+#. Send it.
+#. If somebody gets unsubscribed, it will get unsubscribed only for that
+   event, but including that mail in other event, the registree will still
+   receive mailings.
diff --git a/mass_mailing_custom_unsubscribe_event/static/description/icon.png b/mass_mailing_custom_unsubscribe_event/static/description/icon.png
new file mode 100644
index 000000000..3a0328b51
Binary files /dev/null and b/mass_mailing_custom_unsubscribe_event/static/description/icon.png differ
diff --git a/mass_mailing_custom_unsubscribe_event/static/description/index.html b/mass_mailing_custom_unsubscribe_event/static/description/index.html
new file mode 100644
index 000000000..66899cbe1
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/static/description/index.html
@@ -0,0 +1,439 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+<meta name="generator" content="Docutils 0.15.1: http://docutils.sourceforge.net/" />
+<title>Allow to unsubscribe discretely from an event</title>
+<style type="text/css">
+
+/*
+:Author: David Goodger (goodger@python.org)
+:Id: $Id: html4css1.css 7952 2016-07-26 18:15:59Z milde $
+:Copyright: This stylesheet has been placed in the public domain.
+
+Default cascading style sheet for the HTML output of Docutils.
+
+See http://docutils.sf.net/docs/howto/html-stylesheets.html for how to
+customize this style sheet.
+*/
+
+/* used to remove borders from tables and images */
+.borderless, table.borderless td, table.borderless th {
+  border: 0 }
+
+table.borderless td, table.borderless th {
+  /* Override padding for "table.docutils td" with "! important".
+     The right padding separates the table cells. */
+  padding: 0 0.5em 0 0 ! important }
+
+.first {
+  /* Override more specific margin styles with "! important". */
+  margin-top: 0 ! important }
+
+.last, .with-subtitle {
+  margin-bottom: 0 ! important }
+
+.hidden {
+  display: none }
+
+.subscript {
+  vertical-align: sub;
+  font-size: smaller }
+
+.superscript {
+  vertical-align: super;
+  font-size: smaller }
+
+a.toc-backref {
+  text-decoration: none ;
+  color: black }
+
+blockquote.epigraph {
+  margin: 2em 5em ; }
+
+dl.docutils dd {
+  margin-bottom: 0.5em }
+
+object[type="image/svg+xml"], object[type="application/x-shockwave-flash"] {
+  overflow: hidden;
+}
+
+/* Uncomment (and remove this text!) to get bold-faced definition list terms
+dl.docutils dt {
+  font-weight: bold }
+*/
+
+div.abstract {
+  margin: 2em 5em }
+
+div.abstract p.topic-title {
+  font-weight: bold ;
+  text-align: center }
+
+div.admonition, div.attention, div.caution, div.danger, div.error,
+div.hint, div.important, div.note, div.tip, div.warning {
+  margin: 2em ;
+  border: medium outset ;
+  padding: 1em }
+
+div.admonition p.admonition-title, div.hint p.admonition-title,
+div.important p.admonition-title, div.note p.admonition-title,
+div.tip p.admonition-title {
+  font-weight: bold ;
+  font-family: sans-serif }
+
+div.attention p.admonition-title, div.caution p.admonition-title,
+div.danger p.admonition-title, div.error p.admonition-title,
+div.warning p.admonition-title, .code .error {
+  color: red ;
+  font-weight: bold ;
+  font-family: sans-serif }
+
+/* Uncomment (and remove this text!) to get reduced vertical space in
+   compound paragraphs.
+div.compound .compound-first, div.compound .compound-middle {
+  margin-bottom: 0.5em }
+
+div.compound .compound-last, div.compound .compound-middle {
+  margin-top: 0.5em }
+*/
+
+div.dedication {
+  margin: 2em 5em ;
+  text-align: center ;
+  font-style: italic }
+
+div.dedication p.topic-title {
+  font-weight: bold ;
+  font-style: normal }
+
+div.figure {
+  margin-left: 2em ;
+  margin-right: 2em }
+
+div.footer, div.header {
+  clear: both;
+  font-size: smaller }
+
+div.line-block {
+  display: block ;
+  margin-top: 1em ;
+  margin-bottom: 1em }
+
+div.line-block div.line-block {
+  margin-top: 0 ;
+  margin-bottom: 0 ;
+  margin-left: 1.5em }
+
+div.sidebar {
+  margin: 0 0 0.5em 1em ;
+  border: medium outset ;
+  padding: 1em ;
+  background-color: #ffffee ;
+  width: 40% ;
+  float: right ;
+  clear: right }
+
+div.sidebar p.rubric {
+  font-family: sans-serif ;
+  font-size: medium }
+
+div.system-messages {
+  margin: 5em }
+
+div.system-messages h1 {
+  color: red }
+
+div.system-message {
+  border: medium outset ;
+  padding: 1em }
+
+div.system-message p.system-message-title {
+  color: red ;
+  font-weight: bold }
+
+div.topic {
+  margin: 2em }
+
+h1.section-subtitle, h2.section-subtitle, h3.section-subtitle,
+h4.section-subtitle, h5.section-subtitle, h6.section-subtitle {
+  margin-top: 0.4em }
+
+h1.title {
+  text-align: center }
+
+h2.subtitle {
+  text-align: center }
+
+hr.docutils {
+  width: 75% }
+
+img.align-left, .figure.align-left, object.align-left, table.align-left {
+  clear: left ;
+  float: left ;
+  margin-right: 1em }
+
+img.align-right, .figure.align-right, object.align-right, table.align-right {
+  clear: right ;
+  float: right ;
+  margin-left: 1em }
+
+img.align-center, .figure.align-center, object.align-center {
+  display: block;
+  margin-left: auto;
+  margin-right: auto;
+}
+
+table.align-center {
+  margin-left: auto;
+  margin-right: auto;
+}
+
+.align-left {
+  text-align: left }
+
+.align-center {
+  clear: both ;
+  text-align: center }
+
+.align-right {
+  text-align: right }
+
+/* reset inner alignment in figures */
+div.align-right {
+  text-align: inherit }
+
+/* div.align-center * { */
+/*   text-align: left } */
+
+.align-top    {
+  vertical-align: top }
+
+.align-middle {
+  vertical-align: middle }
+
+.align-bottom {
+  vertical-align: bottom }
+
+ol.simple, ul.simple {
+  margin-bottom: 1em }
+
+ol.arabic {
+  list-style: decimal }
+
+ol.loweralpha {
+  list-style: lower-alpha }
+
+ol.upperalpha {
+  list-style: upper-alpha }
+
+ol.lowerroman {
+  list-style: lower-roman }
+
+ol.upperroman {
+  list-style: upper-roman }
+
+p.attribution {
+  text-align: right ;
+  margin-left: 50% }
+
+p.caption {
+  font-style: italic }
+
+p.credits {
+  font-style: italic ;
+  font-size: smaller }
+
+p.label {
+  white-space: nowrap }
+
+p.rubric {
+  font-weight: bold ;
+  font-size: larger ;
+  color: maroon ;
+  text-align: center }
+
+p.sidebar-title {
+  font-family: sans-serif ;
+  font-weight: bold ;
+  font-size: larger }
+
+p.sidebar-subtitle {
+  font-family: sans-serif ;
+  font-weight: bold }
+
+p.topic-title {
+  font-weight: bold }
+
+pre.address {
+  margin-bottom: 0 ;
+  margin-top: 0 ;
+  font: inherit }
+
+pre.literal-block, pre.doctest-block, pre.math, pre.code {
+  margin-left: 2em ;
+  margin-right: 2em }
+
+pre.code .ln { color: grey; } /* line numbers */
+pre.code, code { background-color: #eeeeee }
+pre.code .comment, code .comment { color: #5C6576 }
+pre.code .keyword, code .keyword { color: #3B0D06; font-weight: bold }
+pre.code .literal.string, code .literal.string { color: #0C5404 }
+pre.code .name.builtin, code .name.builtin { color: #352B84 }
+pre.code .deleted, code .deleted { background-color: #DEB0A1}
+pre.code .inserted, code .inserted { background-color: #A3D289}
+
+span.classifier {
+  font-family: sans-serif ;
+  font-style: oblique }
+
+span.classifier-delimiter {
+  font-family: sans-serif ;
+  font-weight: bold }
+
+span.interpreted {
+  font-family: sans-serif }
+
+span.option {
+  white-space: nowrap }
+
+span.pre {
+  white-space: pre }
+
+span.problematic {
+  color: red }
+
+span.section-subtitle {
+  /* font-size relative to parent (h1..h6 element) */
+  font-size: 80% }
+
+table.citation {
+  border-left: solid 1px gray;
+  margin-left: 1px }
+
+table.docinfo {
+  margin: 2em 4em }
+
+table.docutils {
+  margin-top: 0.5em ;
+  margin-bottom: 0.5em }
+
+table.footnote {
+  border-left: solid 1px black;
+  margin-left: 1px }
+
+table.docutils td, table.docutils th,
+table.docinfo td, table.docinfo th {
+  padding-left: 0.5em ;
+  padding-right: 0.5em ;
+  vertical-align: top }
+
+table.docutils th.field-name, table.docinfo th.docinfo-name {
+  font-weight: bold ;
+  text-align: left ;
+  white-space: nowrap ;
+  padding-left: 0 }
+
+/* "booktabs" style (no vertical lines) */
+table.docutils.booktabs {
+  border: 0px;
+  border-top: 2px solid;
+  border-bottom: 2px solid;
+  border-collapse: collapse;
+}
+table.docutils.booktabs * {
+  border: 0px;
+}
+table.docutils.booktabs th {
+  border-bottom: thin solid;
+  text-align: left;
+}
+
+h1 tt.docutils, h2 tt.docutils, h3 tt.docutils,
+h4 tt.docutils, h5 tt.docutils, h6 tt.docutils {
+  font-size: 100% }
+
+ul.auto-toc {
+  list-style-type: none }
+
+</style>
+</head>
+<body>
+<div class="document" id="allow-to-unsubscribe-discretely-from-an-event">
+<h1 class="title">Allow to unsubscribe discretely from an event</h1>
+
+<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+!! This file is generated by oca-gen-addon-readme !!
+!! changes will be overwritten.                   !!
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
+<p><a class="reference external" href="https://odoo-community.org/page/development-status"><img alt="Beta" src="https://img.shields.io/badge/maturity-Beta-yellow.png" /></a> <a class="reference external" href="http://www.gnu.org/licenses/agpl-3.0-standalone.html"><img alt="License: AGPL-3" src="https://img.shields.io/badge/licence-AGPL--3-blue.png" /></a> <a class="reference external" href="https://github.com/OCA/social/tree/12.0/mass_mailing_custom_unsubscribe_event"><img alt="OCA/social" src="https://img.shields.io/badge/github-OCA%2Fsocial-lightgray.png?logo=github" /></a> <a class="reference external" href="https://translation.odoo-community.org/projects/social-12-0/social-12-0-mass_mailing_custom_unsubscribe_event"><img alt="Translate me on Weblate" src="https://img.shields.io/badge/weblate-Translate%20me-F47D42.png" /></a> <a class="reference external" href="https://runbot.odoo-community.org/runbot/205/12.0"><img alt="Try me on Runbot" src="https://img.shields.io/badge/runbot-Try%20me-875A7B.png" /></a></p>
+<p>This addon extends the unsubscription process for allowing to unsubscribe
+only for an event.</p>
+<p>Standard process includes the mail in the general blacklist instead, which
+can be very unconvenient.</p>
+<p><strong>Table of contents</strong></p>
+<div class="contents local topic" id="contents">
+<ul class="simple">
+<li><a class="reference internal" href="#usage" id="id1">Usage</a></li>
+<li><a class="reference internal" href="#bug-tracker" id="id2">Bug Tracker</a></li>
+<li><a class="reference internal" href="#credits" id="id3">Credits</a><ul>
+<li><a class="reference internal" href="#authors" id="id4">Authors</a></li>
+<li><a class="reference internal" href="#contributors" id="id5">Contributors</a></li>
+<li><a class="reference internal" href="#maintainers" id="id6">Maintainers</a></li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="usage">
+<h1><a class="toc-backref" href="#id1">Usage</a></h1>
+<ol class="arabic simple">
+<li>Go to <em>Email Marketing &gt; Mailings &gt; Create</em>.</li>
+<li>Select “Event Registration” in <em>Recipients</em> field.</li>
+<li>Edit your mass mailing at wish, but remember to add a snippet from
+<em>Footers</em>, so people have an <em>Unsubscribe</em> link.</li>
+<li>Send it.</li>
+<li>If somebody gets unsubscribed, it will get unsubscribed only for that
+event, but including that mail in other event, the registree will still
+receive mailings.</li>
+</ol>
+</div>
+<div class="section" id="bug-tracker">
+<h1><a class="toc-backref" href="#id2">Bug Tracker</a></h1>
+<p>Bugs are tracked on <a class="reference external" href="https://github.com/OCA/social/issues">GitHub Issues</a>.
+In case of trouble, please check there if your issue has already been reported.
+If you spotted it first, help us smashing it by providing a detailed and welcomed
+<a class="reference external" href="https://github.com/OCA/social/issues/new?body=module:%20mass_mailing_custom_unsubscribe_event%0Aversion:%2012.0%0A%0A**Steps%20to%20reproduce**%0A-%20...%0A%0A**Current%20behavior**%0A%0A**Expected%20behavior**">feedback</a>.</p>
+<p>Do not contact contributors directly about support or help with technical issues.</p>
+</div>
+<div class="section" id="credits">
+<h1><a class="toc-backref" href="#id3">Credits</a></h1>
+<div class="section" id="authors">
+<h2><a class="toc-backref" href="#id4">Authors</a></h2>
+<ul class="simple">
+<li>Tecnativa</li>
+</ul>
+</div>
+<div class="section" id="contributors">
+<h2><a class="toc-backref" href="#id5">Contributors</a></h2>
+<ul class="simple">
+<li><a class="reference external" href="https://www.tecnativa.com">Tecnativa</a>:<ul>
+<li>Pedro M. Baeza</li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="maintainers">
+<h2><a class="toc-backref" href="#id6">Maintainers</a></h2>
+<p>This module is maintained by the OCA.</p>
+<a class="reference external image-reference" href="https://odoo-community.org"><img alt="Odoo Community Association" src="https://odoo-community.org/logo.png" /></a>
+<p>OCA, or the Odoo Community Association, is a nonprofit organization whose
+mission is to support the collaborative development of Odoo features and
+promote its widespread use.</p>
+<p>This module is part of the <a class="reference external" href="https://github.com/OCA/social/tree/12.0/mass_mailing_custom_unsubscribe_event">OCA/social</a> project on GitHub.</p>
+<p>You are welcome to contribute. To learn how please visit <a class="reference external" href="https://odoo-community.org/page/Contribute">https://odoo-community.org/page/Contribute</a>.</p>
+</div>
+</div>
+</div>
+</body>
+</html>
diff --git a/mass_mailing_custom_unsubscribe_event/static/src/js/tour.js b/mass_mailing_custom_unsubscribe_event/static/src/js/tour.js
new file mode 100644
index 000000000..c85adde1d
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/static/src/js/tour.js
@@ -0,0 +1,47 @@
+/* Copyright 2020 Tecnativa - João Marques
+ * License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). */
+odoo.define("mass_mailing_custom_unsubscribe_event.tour",
+    function (require) {
+        "use strict";
+        var base = require("web_editor.base");
+        var tour = require("web_tour.tour");
+
+        // Allow to know if an element is required
+        $.extend($.expr[':'], {
+            propRequired: function (element) {
+                return $(element).prop("required");
+            },
+        });
+
+        tour.register(
+            "mass_mailing_custom_unsubscribe_event_tour",
+            {
+                test: true,
+                wait_for: base.ready(),
+            },
+            [
+                {
+                    content: "Choose other reason",
+                    trigger: ".radio:contains('Other reason') :radio:not(:checked)",
+                    extra_trigger: "#reason_form #custom_div_feedback",
+                },
+                {
+                    content: "Switch to not interested reason",
+                    trigger:
+                        ".radio:contains(\"I'm not interested\") :radio:not(:checked)",
+                    extra_trigger: "[name='details']:propRequired",
+                },
+                {
+                    content: "Unsubscribe",
+                    trigger: "#reason_form button:submit",
+                    extra_trigger: "body:not(:has([name='details']:propRequired))",
+                },
+                {
+                    content: "Successfully unsubscribed",
+                    trigger: "body:not(:has(#reason_form)) #subscription_info " +
+                         ":contains('successfully unsubscribed')",
+                },
+            ]
+        );
+    }
+);
diff --git a/mass_mailing_custom_unsubscribe_event/tests/__init__.py b/mass_mailing_custom_unsubscribe_event/tests/__init__.py
new file mode 100644
index 000000000..d88d3b1a1
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/tests/__init__.py
@@ -0,0 +1,4 @@
+# Copyright 2020 Tecnativa - João Marques
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from . import test_ui
diff --git a/mass_mailing_custom_unsubscribe_event/tests/test_ui.py b/mass_mailing_custom_unsubscribe_event/tests/test_ui.py
new file mode 100644
index 000000000..8b62418bd
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/tests/test_ui.py
@@ -0,0 +1,154 @@
+# Copyright 2020 Tecnativa - João Marques
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+import mock
+from werkzeug import urls
+
+from odoo.tests.common import HttpCase
+
+
+class UICase(HttpCase):
+    def extract_url(self, mail, *args, **kwargs):
+        url = mail._get_unsubscribe_url(self.email)
+        self.assertTrue(urls.url_parse(url).decode_query().get("token"))
+        self.assertTrue(url.startswith(self.domain))
+        self.url = url.replace(self.domain, "", 1)
+        return True
+
+    def setUp(self):
+        super(UICase, self).setUp()
+        self.email = "test.contact@example.com"
+        self.mail_postprocess_patch = mock.patch(
+            "odoo.addons.mass_mailing.models.mail_mail.MailMail."
+            "_postprocess_sent_message",
+            autospec=True,
+            side_effect=self.extract_url,
+        )
+
+        self.domain = self.env["ir.config_parameter"].get_param("web.base.url")
+
+        self.partner = self.env["res.partner"].create(
+            {"name": "Demo Partner <%s>" % self.email, "email": self.email}
+        )
+
+        self.event_1 = self.env["event.event"].create(
+            {
+                "name": "test_event_2",
+                "event_type_id": 1,
+                "date_end": "2012-01-01 19:05:15",
+                "date_begin": "2012-01-01 18:05:15",
+            }
+        )
+        self.event_2 = self.env["event.event"].create(
+            {
+                "name": "test_event_2",
+                "event_type_id": 1,
+                "date_end": "2012-01-01 19:05:15",
+                "date_begin": "2012-01-01 18:05:15",
+            }
+        )
+        self.event_registration_1 = self.env["event.registration"].create(
+            {
+                "name": "test_registration_1",
+                "event_id": self.event_1.id,
+                "email": self.email,
+                "partner_id": self.partner.id,
+            }
+        )
+        self.event_registration_2 = self.env["event.registration"].create(
+            {
+                "name": "test_registration_2",
+                "event_id": self.event_2.id,
+                "email": self.email,
+                "partner_id": self.partner.id,
+            }
+        )
+
+        self.mailing_1 = self.env["mailing.mailing"].create(
+            {
+                "name": "test_mailing_1",
+                "mailing_model_id": self.env.ref("event.model_event_registration").id,
+                "mailing_domain": "[['id','=',%s]]" % self.event_registration_1.id,
+                "reply_to_mode": "email",
+                "subject": "Test 1",
+            }
+        )
+        self.mailing_1._onchange_model_and_list()
+        # HACK https://github.com/odoo/odoo/pull/14429
+        self.mailing_1.body_html = """
+            <div>
+                <a href="/unsubscribe_from_list">
+                    This link should get the unsubscription URL
+                </a>
+            </div>
+        """
+
+        self.mailing_2 = self.env["mailing.mailing"].create(
+            {
+                "name": "test_mailing_2",
+                "mailing_model_id": self.env.ref("event.model_event_registration").id,
+                "mailing_domain": "[['id','=',%s]]" % self.event_registration_2.id,
+                "reply_to_mode": "email",
+                "subject": "Test 2",
+            }
+        )
+        self.mailing_2._onchange_model_and_list()
+        # HACK https://github.com/odoo/odoo/pull/14429
+        self.mailing_2.body_html = """
+            <div>
+                <a href="/unsubscribe_from_list">
+                    This link should get the unsubscription URL
+                </a>
+            </div>
+        """
+
+    def tearDown(self):
+        del (
+            self.email,
+            self.event_1,
+            self.event_2,
+            self.event_registration_1,
+            self.event_registration_2,
+            self.mailing_1,
+            self.mailing_2,
+            self.partner,
+            self.url,
+        )
+        super(UICase, self).tearDown()
+
+    def test_unsubscription_event_1(self):
+        """Test a mass mailing contact that wants to unsubscribe."""
+        # Extract the unsubscription link from the message body
+        with self.mail_postprocess_patch:
+            self.mailing_1.action_send_mail()
+
+        tour = "mass_mailing_custom_unsubscribe_event_tour"
+        self.start_tour(url_path=self.url, tour_name=tour, login="demo")
+
+        # Check results from running tour
+        # User should be opted out from event 1 mailing list
+        self.assertTrue(self.event_registration_1.opt_out)
+        # User should not be opted out from event 2 mailing list
+        self.assertFalse(self.event_registration_2.opt_out)
+
+        reason_xid = "mass_mailing_custom_unsubscribe.reason_not_interested"
+        unsubscriptions = self.env["mail.unsubscription"].search(
+            [
+                ("action", "=", "unsubscription"),
+                ("mass_mailing_id", "=", self.mailing_1.id),
+                ("email", "=", self.email),
+                (
+                    "unsubscriber_id",
+                    "=",
+                    "event.registration,%d" % self.event_registration_1.id,
+                ),
+                ("details", "=", False),
+                ("reason_id", "=", self.env.ref(reason_xid).id),
+            ]
+        )
+        # Unsubscription record must exist
+        self.assertEqual(1, len(unsubscriptions))
+
+        self.mailing_2.action_send_mail()
+
+        # Mail to user must have been sent
+        self.assertEqual(1, self.mailing_2.sent)
diff --git a/mass_mailing_custom_unsubscribe_event/views/event_registration_views.xml b/mass_mailing_custom_unsubscribe_event/views/event_registration_views.xml
new file mode 100644
index 000000000..e754a1d33
--- /dev/null
+++ b/mass_mailing_custom_unsubscribe_event/views/event_registration_views.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2020 Tecnativa - Pedro M. Baeza
+     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). -->
+
+<odoo>
+
+    <record id="view_event_registration_form" model="ir.ui.view">
+        <field name="name">event.registration.form - Add opt_out</field>
+        <field name="model">event.registration</field>
+        <field name="inherit_id" ref="event.view_event_registration_form"/>
+        <field name="arch" type="xml">
+            <field name="email" position="after">
+                <field name="opt_out" />
+            </field>
+        </field>
+    </record>
+
+</odoo>