open the files without them having any chance of interent conention and cant see other files Use a VM and don't give it internet connectivity.

I use Tuta because Proton has grown too big for my taste. What do you mean it doesn't work with Tor? Tor is supposed to be your network layer foundation of your connection and shouldn't have to do with what applications you run on top of it. And just to clarify: Simple Login is not an e-mail provider. It's an e-mail alias provider.