flectra/addons/mail/views/mail_message_views.xml

<?xml version="1.0"?>
<flectra>
    <data>
        <!-- mail.message tree: short view !-->
        <record model="ir.ui.view" id="view_message_tree">
            <field name="name">mail.message.tree</field>
            <field name="model">mail.message</field>
            <field name="priority">20</field>
            <field name="arch" type="xml">
                <tree string="Messages">
                    <field name="date"/>
                    <field name="subject"/>
                    <field name="author_id"/>
                    <field name="model"/>
                    <field name="res_id"/>
                </tree>
            </field>
        </record>

        <!-- mail.message form: short view !-->
        <record model="ir.ui.view" id="view_message_form">
            <field name="name">mail.message.form</field>
            <field name="model">mail.message</field>
            <field name="priority">20</field>
            <field name="arch" type="xml">
                <form string="Message">
                    <sheet>
                        <group>
                            <group>
                                <field name="subject"/>
                                <field name="date"/>
                                <field name="email_from"/>
                                <field name="author_id"/>
                                <field name="record_name"/>
                            </group>
                            <group>
                                <field name="parent_id"/>
                                <field name="model"/>
                                <field name="res_id"/>
                                <field name="message_type"/>
                                <field name="subtype_id"/>
                            </group>
                        </group>
                        <notebook>
                            <page string="Body">
                                <field name="body" options="{'style-inline': true}"/>
                            </page>
                            <page string="Gateway">
                                <group>
                                    <group>
                                        <field name="reply_to"/>
                                        <field name="no_auto_thread"/>
                                    </group>
                                    <group>
                                        <field name="message_id"/>
                                        <field name="mail_server_id"/>
                                    </group>
                                </group>
                            </page>
                            <page string="Recipients">
                                <group>
                                    <group>
                                        <field name="partner_ids" widget="many2many_tags"/>
                                        <field name="channel_ids" widget="many2many_tags"/>
                                    </group>
                                    <group>
                                        <field name="needaction_partner_ids" widget="many2many_tags"/>
                                        <field name="starred_partner_ids" widget="many2many_tags"/>
                                    </group>
                                </group>
                                <group>
                                    <field name="notification_ids">
                                        <tree>
                                            <field name="res_partner_id"/>
                                            <field name="is_read"/>
                                            <field name="is_email"/>
                                            <field name="email_status"/>
                                        </tree>
                                    </field>
                                </group>
                            </page>
                            <page string="Tracking">
                                <field name="tracking_value_ids"/>
                            </page>
                        </notebook>
                    </sheet>
                </form>
            </field>
        </record>

        <!-- mail.message search: wall view !-->
        <record model="ir.ui.view" id="view_message_search">
            <field name="name">mail.message.search</field>
            <field name="model">mail.message</field>
            <field name="priority">25</field>
            <field name="arch" type="xml">
                <search string="Messages Search">
                    <field name="body" string="Content" filter_domain="['|', ('subject', 'ilike', self), ('body', 'ilike', self)]" />
                    <field name="subject"/>
                    <field name="message_type"/>
                    <field name="author_id"/>
                    <field name="partner_ids"/>
                    <field name="model"/>
                    <field name="res_id"/>
                    <field name="parent_id"/>
                    <filter string="Has Mentions"
                            name="filter_has_mentions"
                            domain="[('partner_ids.user_ids', 'in', [uid])]"/>
                    <separator/>
                    <filter string="Need Action"
                            name="message_needaction" help="Unread messages"
                            domain="[('needaction', '=', True)]"/>
                    <separator/>
                    <filter string="Has attachments"
                            name="attachments"
                            domain="[('attachment_ids', '!=', False)]"/>
                </search>
            </field>
        </record>

        <record id="action_view_mail_message" model="ir.actions.act_window">
            <field name="name">Messages</field>
            <field name="res_model">mail.message</field>
            <field name="view_type">form</field>
            <field name="view_mode">tree,form</field>
            <field name="search_view_id" ref="view_message_search"/>
        </record>
        
        <!-- Add menu entry in Settings/Email -->
        <menuitem name="Messages" id="menu_mail_message" parent="base.menu_email" action="action_view_mail_message"/>

        <record model="ir.ui.view" id="view_document_file_kanban">
            <field name="name">ir.attachment kanban</field>
            <field name="model">ir.attachment</field>
            <field name="arch" type="xml">
                <kanban>
                    <field name="id"/>
                    <field name="mimetype"/>
                    <field name="type"/>
                    <field name="datas_fname"/>
                    <field name="name"/>
                    <templates>
                        <t t-name="kanban-box">
                            <div class="oe_kanban_global_click">
                                <div class="oe_kanban_vignette">
                                    <div class="oe_attachment">
                                        <div class="oe_name">
                                            <field name="name"/>
                                        </div>
                                        <div t-if="record.type.raw_value == 'binary'">
                                            <a t-attf-href="/web/content/#{record.id.raw_value}?download=1">
                                                <t t-set="webimage" t-value="new RegExp('image.*(gif|jpeg|jpg|png)').test(record.mimetype.value)"/>
                                                <div t-if="!webimage" class="o_image" t-att-data-mimetype="record.mimetype.value"/>
                                                <div t-if="webimage" class="o_attachment_image">
                                                    <img t-attf-src="/web/image/#{record.id.raw_value}?download=1"/>
                                                </div>
                                            </a>
                                        </div>
                                    </div>
                                </div>
                            </div>
                        </t>
                    </templates>
                </kanban>
            </field>
        </record>
        <record id="base.action_attachment" model="ir.actions.act_window">
            <field name="view_mode">kanban,tree,form</field>
            <field name="help" type="html">
              <p class="oe_view_nocontent_create">
                Click here to attach a new document.
              </p>
            </field>
        </record>

    </data>
</flectra>