The twelve words are translated to the bitcoin addresses in a wallet. So in a form that is indeed the un-encrypted wallet and should be encrypted during transmission.

It's not recommended to transmit these words over the internet for obvious reasons, especially since this will not only expose the initially funded addresses but all addresses that can ever be created for this wallet. It's way worse then leaking just the private key for one address.

Something like Bitcoin paper wallet might be better, although that won't work with Electrum.