[bigs]

From the FAQ it appears to be similar to Protonmail - emails stored on their servers, however the key “decentralized” difference being that you locally hold the encryption key so any attack on the server can’t decrypt the emails as you hold the key (unlike Protonmail who holds them).

I don’t know the tech details of either product myself I’ve just re-iterated their FAQ entry.

[userisatester]

You’re spot on! Arca encrypts emails locally, and you hold the keys. This means even if servers are attacked, your data stays secure because only you can decrypt it—unlike ProtonMail, where they manage the keys.

[cchance]

I don't think its hosted on their servers, they don't mention that specifically its software, thats why the mac version requires MacFUSE for a secure encrypted drive for the at-rest security

[userisatester]

You’re right! Arca isn’t hosted on their servers, it’s software you run locally. The mention of MacFUSE is for creating a secure, encrypted drive on your device, ensuring your data remains protected even at rest.