flectra/addons/mail/views/res_partner_views.xml

<?xml version="1.0" ?>
<flectra>
    <data>

        <record id="res_partner_view_form_inherit_mail" model="ir.ui.view">
            <field name="name">res.partner.view.form.inherit.mail</field>
            <field name="model">res.partner</field>
            <field name="inherit_id" ref="base.view_partner_form"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='user_id']" position="after">
                    <field name="opt_out" string="Mailing Opt-Out" groups="base.group_no_one"/>
                    <field name="message_bounce" groups="base.group_no_one"/>
                </xpath>
                <xpath expr="//sheet" position="after">
                    <div class="oe_chatter">
                        <field name="message_follower_ids" widget="mail_followers"/>
                        <field name="activity_ids" widget="mail_activity"/>
                        <field name="message_ids" widget="mail_thread"/>
                    </div>
                </xpath>
            </field>
        </record>

       <record id="res_partner_view_search_inherit_mail" model="ir.ui.view">
            <field name="name">res.partner.view.search.inherit.mail</field>
            <field name="model">res.partner</field>
            <field name="inherit_id" ref="base.view_res_partner_filter"/>
            <field name="arch" type="xml">
                    <filter name="supplier" position="after">
                        <separator />
                        <filter string="Available for mass mailing"
                                name='not_opt_out' domain="[('opt_out', '=', False)]"
                                help="Partners that did not ask not to be included in mass mailing campaigns" />
                        <separator/>
                        <filter string="My Activities" name="activities_my"
                                domain="[('activity_ids.user_id', '=', uid)]"/>
                        <separator/>
                        <filter string="Late Activities" name="activities_overdue"
                                domain="[('activity_ids.date_deadline', '&lt;', context_today().strftime('%Y-%m-%d'))]"
                                help="Show all records which has next action date is before today"/>
                        <filter string="Today Activities" name="activities_today"
                                domain="[('activity_ids.date_deadline', '=', context_today().strftime('%Y-%m-%d'))]"/>
                        <filter string="Future Activities" name="activities_upcoming_all"
                                domain="[('activity_ids.date_deadline', '&gt;', context_today().strftime('%Y-%m-%d'))
                        ]"/>
                        <separator/>
                    </filter>
            </field>
        </record>

        <!--Definition of an email template with an empty body that will be used in partner mailing. Used to give a
            basis for email recipients, name and to ease the definition of a further elaborated template. -->
        <record id="email_template_partner" model="mail.template">
            <field name="name">Partner Mass Mail</field>
            <field name="model_id" ref="base.model_res_partner"/>
            <field name="auto_delete" eval="True"/>
            <field name="partner_to">${object.id}</field>
        </record>

        <!--  Replace the default mass-mailing wizard in base with the composition wizard -->
        <act_window name="Partner Mass Mailing"
                res_model="mail.compose.message"
                src_model="res.partner"
                view_mode="form"
                multi="True"
                target="new"
                key2="client_action_multi"
                id="action_partner_mass_mail"
                context="{
                            'default_composition_mode': 'mass_mail',
                            'default_partner_to': '${object.id or \'\'}',
                            'default_use_template': True,
                            'default_template_id': ref('email_template_partner'),
                        }"/>

        <record id="email_template_partner" model="mail.template">
            <field name="ref_ir_act_window" ref="action_partner_mass_mail"/>
        </record>

    </data>
</flectra>