I would like to send email to customer but i dont want to create said email in record chatter as well.

I think this is the method responsible (although i might be wrong).

def _send_email_notification(self, ticket):
    reminder_template = self.env.ref('module.mail_template')
        email_values = {'email_to': self.partner_id.email}
        reminder_template.sudo().send_mail(ticket.id, force_send=True, email_values=email_values)