Is it possible to prevent the user from changing the subject when using the fep_shortcode_new_message_form shortcode? I need to associate an ID (from my web app) with the message/post ID generated by fep. At the moment the only way I can see of doing this is to embed the ID into the subject of the fep message but then there is the risk that the user changes it. Using CSS to hide it is not robust as someone could unhide it from their browser if they so wished.
Ideally I would like to pass my ID to fep so that when it creates the first message, it stores my ID as a post_meta data. Is that possible?