I have an account but don't really use it. The lack of support for desktop clients, while understandable, kills it for me.
Also, for the record, they're now the maintainers of OpenPGPjs not OpenPGP [0].
Their servers do not decrypt your email, thus doing so requires support from the client. The browser currently does this on your machine. Do desktop clients support decrypting email? Can we trust these clients won't store your emails in plain-text on your machine? Or that they won't mistakenly leak your information via some other channels?
I agree desktop client support is a nice feature to have, but I am not sure it is trivial to make happen.
Sorry, I should have been more clear. I'm aware that it's not trivial to implement since they rely so much on the aforementioned OpenPGPjs library and that they're also working on implementing IMAP support. I just meant that the lack of desktop client support killed it for me currently. Once I can plug it into Thunderbird, preferably with an extension of some kind to keep things encrypted, I'll switch to it as my primary email.
Though I am curious as to why you think that's their problem. From what I can tell Protonmail promises that the mail is encrypted on their servers and that accessing it through the official methods (i.e. the website and mobile apps) is also encrypted. While I admire their apparent commitment to extending such promises to the desktop, I'm also surprised they didn't whip up an IMAP interface (which I image would be simpler; send the passphrase to decrypt the mailbox then send the emails like normal) and say "This is for unofficial access, we make no promises".
I'm also iffy on the fact that they don't have an export function. Especially with GhostMail switching to enterprise-only, I am very wary about trusting a webmail service that won't let me back up my emails locally in case they "disappear".
This is the traditional workflow for PGP-encrypted email, and has been for decades. Protonmail chose to be incompatible with this established standard.
> Protonmail chose to be incompatible with this established standard.
They've supported receiving PGP-encrypted emails[1] and are working on IMAP support currently[2]. Would be nice for you to cite sources before making strong claims like "chose to be incompatible". Everything is a feature and needs time to implement.
[0]:https://protonmail.com/blog/openpgpjs-email-encryption/