social/mail_edit/views/compose_message.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data>

<record id="mail_edit_form" model="ir.ui.view">
    <field name="name">Edit Email Form</field>
    <field name="model">mail.message</field>
    <field name="arch" type="xml">
        <form string="Message" create="false">
            <sheet>
                <group>
                    <group>
                        <field name="subject" groups="mail_edit.group_mail_edit_editor,mail_edit.group_mail_edit_superuser"/>
                        <field name="date" readonly="1"/>
                        <field name="type" readonly="1"/>
                        <field name="subtype_id" readonly="1"/>
                    </group>
                    <group>
                        <field name="destination_object_id" required="1" groups="mail_edit.group_mail_edit_mover,mail_edit.group_mail_edit_superuser"/>
                        <field name="model" invisible="1"/>
                        <field name="res_id" invisible="1"/>
                        <field name="parent_id" readonly="1" />
                    </group>
                </group>
                <field name="body" groups="mail_edit.group_mail_edit_editor,mail_edit.group_mail_edit_superuser"/>
            </sheet>
        </form>
    </field>
</record>

<record id="mail_edit_action" model="ir.actions.act_window">
    <field name="name">Edit or Move Message</field>
    <field name="res_model">mail.message</field>
    <field name="type">ir.actions.act_window</field>
    <field name="view_id" ref="mail_edit_form"/>
    <field name="view_type">form</field>
    <field name="view_mode">form</field>
    <field name="target">new</field>
</record>

</data>
</openerp>