res_user_views.xml

<!-- Copyright 2022 AdHoc SA
    License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html). -->
<odoo>

    <record id="view_users_form_mail" model="ir.ui.view">
        <field name="name">res.users.form.user.forwarding</field>
        <field name="model">res.users</field>
        <field name="inherit_id" ref="base.view_users_form" />
        <field name="arch" type="xml">
            <xpath expr="//field[@name='login']//.." position="after">
                <label for="forwarding_partner_id" />
                <field name="forwarding_partner_id" />
            </xpath>
        </field>
    </record>

    <record id="view_users_form_mail_preferences" model="ir.ui.view">
        <field name="name">res.users.form.user.forwarding.preferences</field>
        <field name="model">res.users</field>
        <field name="inherit_id" ref="base.view_users_form_simple_modif" />
        <field name="arch" type="xml">
            <field name="email" position="after">
                <field name="forwarding_partner_id" readonly="0" />
            </field>
        </field>
    </record>

</odoo>