In purchase, we send a mail for RFQ, Purchase order but first, we have the option for composing it from a template. We use mail.template for it. Should we use mail.mail or mail.message for sending  it when i do not want to give user an option for editing.....i.e. an email will go automatically to admin group  when user click a particular button. I am not being able to configure the group based email in 'email into field'!!!!!

<field name="email_to">${object.partner_id.id}</field>    is there anyway to send email based on group using some code here?