smtp_per_user/smtp_per_user_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="ir_mail_server_form" model="ir.ui.view">
            <field name="model">ir.mail_server</field>
            <field name="inherit_id" ref="base.ir_mail_server_form"/>
            <field name="arch" type="xml">
                <field name="smtp_user" position="before">
                    <field name="force_use"/>
                    <field name="email_name"/>
                    <field name="user_id"/>
                </field>
            </field>
        </record>
    </data>
</openerp>