social/mail_tracking_mass_mailing/views/mail_mass_mailing_view.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- © 2016 Antonio Espinosa - <antonio.espinosa@tecnativa.com>
     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html). -->
<openerp>
<data>

<record model="ir.ui.view" id="view_mail_mass_mailing_form">
    <field name="name">Add avoid resend field</field>
    <field name="model">mail.mass_mailing</field>
    <field name="inherit_id" ref="mass_mailing.view_mail_mass_mailing_form"/>
    <field name="arch" type="xml">
        <field name="mass_mailing_campaign_id" position="before">
            <field name="avoid_resend"/>
        </field>
    </field>
</record>

</data>
</openerp>