As these people were using an email account supplied by the school district, the simple solution is to automatically make all of the email from each board member public facing. Something similar to google groups email would work. They can discuss things all they want, and it is all in 'public' as it is available right away.
I've been using a Faraday Cage wallet and passport holder by DIFRwear: http://difrwear.com/ for several years now. I don't work for them, but with the very cheap wallet prices and sturdy construction I've been very pleased with the products. I can testify that they do work as I have an RFID key card and it won't activate the door if in the wallet.