bemade-addons/bemade_mailcow_integration/views/res_users_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record id="view_users_form_mailcow" model="ir.ui.view">
        <field name="name">res.users.mailcow.form</field>
        <field name="model">res.users</field>
        <field name="inherit_id" ref="base.view_users_form"/>
        <field name="arch" type="xml">
            <field name="email" position="before">
                <div id="mailcow_mailcow" attrs="{'invisible': [('id', '!=', False)]}">
                    <label for="mailcow_mailbox" string="Create mailbox on Mailcow"/>
                    <field name="mailcow_mailbox"/>
                </div>
            </field>
        </field>
    </record>
</odoo>