One key principle for Helm is that you always hold your encryption keys to all your data— Helm and outside parties should never get access to that. So the backups are encrypted, and the Helm device itself stores your data in an encrypted fashion on its storage, and has a secure enclave such that those keys never enter user memory space.

Hosted services like protonmail (great option) support some key management but that's rare. Most everyone stores all your data in the clear, and that sets you up for Facebook-style hacks where people just steal a database en masse, and/or leave you open to warrantless wiretap which has been a problem for email services broadly in the past.

I want to point out that email is just the first part of what Helm wants to do. What is super valuable is that Helm can run its own software and add things like distributed anonymized VPN, or file sharing, and these things are all federated in a way that wasn't possible before.

Not everyone is going to care about this, but enough people should. People reading this thread should care: decentralization and federation of this sort is the way we maintain an open Internet. You can take down individual nodes but you can't take down millions of them. That's the ultimate goal of Helm.

Remember, there's no such thing as a cloud, it's just someone else's computer.