<record id="action_discuss" model="ir.actions.client">
        <field name="name">Discuss</field>
        <field name="tag">mail.discuss</field>
        <field name="res_model">mail.channel</field>
        <field name="params" eval="&quot;{
            'default_active_id': 'mailbox_inbox'
        }&quot;"/>
    </record>

<menuitem
    id="mail.menu_root_discuss"
    name="Discuss"
    action="action_discuss"
    web_icon="mail,static/description/icon.png"
    groups="base.group_user"
    sequence="1"/>