For a critical blog, the first few paragraphs sound a lot like they're shilling for Proton.
I'm not sure if I'm supposed to be impressed by the author's witty wording, but "the cool trick they do" is - full encryption.
Moving on.
But that’s misleading. The actual large language model is not open. The code for Proton’s bit of Lumo is not open source. The only open source bit that Proton’s made available is just some of Proton’s controls for the LLM. [GitHub]
In the single most damning thing I can say about Proton in 2025, the Proton GitHub repository has a “cursorrules” file. They’re vibe-coding their public systems. Much secure!
oof.
Over the years I've heard many people claim that proton's servers being in Switzerland is more secure than other EU countries - well there's also this now:
Proton is moving its servers out of Switzerland to another country in the EU they haven’t specified. The Lumo announcement is the first that Proton’s mentioned this.
No company is safe from enshittification - always look for, and base your choices on, the legally binding stuff, before you commit. Be wary of weasel wording. And always, always be ready to move* on when the enshittification starts despite your caution.
* regarding email, there's redirection services a.k.a. eternal email addresses - in some cases run by venerable non-profits.