social/mail_sendgrid_mass_mailing/views/mass_mailing_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <!-- Form view -->
        <record id="view_email_template_sendgrid_form" model="ir.ui.view">
            <field name="name">mass.mailing.sendgrid.form</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">
                <xpath expr="//field[@name='mailing_model']/.." position="after">
                    <field name="email_template_id" domain="[('model', '=', mailing_model), ('sendgrid_template_ids', '!=', False)]"/>
                    <field name="lang" attrs="{'invisible': [('email_template_id', '=', False)]}"/>
                </xpath>
                <xpath expr="//notebook/page[1]" position="after">
                    <page string="Sendgrid Preview" attrs="{'invisible': [('email_template_id', '=', False)]}">
                        <field name="html_copy" invisible="1"/>
                        <field name="body_sendgrid" widget="html"/>
                    </page>
                </xpath>
                <xpath expr="//notebook/page/group[1]">
                    <group string="Sendgrid Unsubscribe">
                        <field name="enable_unsubscribe"/>
                        <field name="unsubscribe_text" attrs="{'invisible': [('enable_unsubscribe', '=', False)]}"/>
                        <field name="unsubscribe_tag" attrs="{'invisible': [('enable_unsubscribe', '=', False)]}"/>
                    </group>
                </xpath>
            </field>
        </record>

    </data>
</openerp>