mail-addons/res_partner_mails_count/templates.xml

<?xml version="1.0"?>
<openerp>
    <data>
        <template id="res_partner_mails_count_assets_backend"
                  name="res_partner_mails_count_assets_backend"
                  inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <script src="/res_partner_mails_count/static/src/js/main.js"
                        type="text/javascript"></script>
            </xpath>
        </template>

        <record id="view_res_partner_mails_count_info_form" model="ir.ui.view">
            <field name="name">res.partner.mails.count</field>
            <field name="model">res.partner</field>
            <field name="inherit_id" ref="base.view_partner_form"/>
            <field name="priority" eval="50"/>
            <field name="arch" type="xml">
                <div name="button_box" position="inside">
                    <button class="oe_stat_button" type="action"
                        name="%(action_mails)d"
                        context="{'search_default_partner_ids': [active_id], 'default_model': 'res.partner', 'default_res_id': active_id}"
                        icon="fa-envelope">
                        <field string="Mails to" name="mails_to" widget="statinfo"/>
                    </button>
                    <button class="oe_stat_button" type="action"
                        name="%(action_mails)d"
                        context="{'search_default_author_id': active_id, 'default_model': 'res.partner', 'default_res_id': active_id}"
                        icon="fa-envelope-o">
                        <field  string="Mails from" name="mails_from" widget="statinfo"/>
                    </button>
                </div>
            </field>
        </record>
    </data>
</openerp>