flectra/addons/mail/views/res_users_views.xml

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

        <!-- Update Preferences form !-->
        <record id="view_users_form_simple_modif_mail" model="ir.ui.view">
            <field name="name">res.users.preferences.form.mail</field>
            <field name="model">res.users</field>
            <field name="inherit_id" ref="base.view_users_form_simple_modif"/>
            <field name="arch" type="xml">
            <data>
                <field name="email" position="before">
                    <field name="notification_type" widget="radio" readonly="0"/>
                </field>
            </data>
            </field>
        </record>

        <!-- Update user form !-->
        <record id="view_users_form_mail" model="ir.ui.view">
            <field name="name">res.users.form.mail</field>
            <field name="model">res.users</field>
            <field name="inherit_id" ref="base.view_users_form"/>
            <field name="arch" type="xml">
                <data>
                    <field name="signature" position="before">
                        <field name="notification_type" widget="radio"/>
                    </field>
                    <field name="signature" position="before">
                        <field name="alias_id"/>
                        <field name="alias_contact" attrs="{'invisible': [('alias_id', '=', False)]}"/>
                    </field>
                </data>
            </field>
        </record>

    </data>
</flectra>