mail-addons/res_partner_mails_count/views/res_partner_mails_count.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data>
        <record id="action_mails" model="ir.actions.client">
            <field name="name">Mails</field>
            <field name="tag">mail.chat.instant_messaging</field>
            <field name="res_model">mail.message</field>
            <field name="context">{
                'ignore_search_model': True,
            }</field>
            <field name="help" type="html">
                <p>
                    Mails not found. Probably, they exist, but you don't have access.
                </p>
            </field>
        </record>

        <!--<record id="action_mails" model="ir.actions.act_window">-->
            <!--<field name="name">Mails</field>-->
            <!--<field name="res_model">mail.message</field>-->
            <!--<field name="context">{-->
                <!--'ignore_search_model': True,-->
            <!--}</field>-->
            <!--<field name="help" type="html">-->
                <!--<p>-->
                    <!--Mails not found. Probably, they exist, but you don't have access.-->
                <!--</p>-->
            <!--</field>-->
        <!--</record>-->

    </data>
</openerp>