[lugubris]

> what happens if they are bought

Not going to happen overnight and even then technically they cannot access your emails because only you hold the password to private keys (if you trust they encrypt your emails with your public key before storing). I prefer keeping my emails local so pop does the job.

Google can access your emails but something like protonmail can't (if you trust them to encrypt your emails).

[thiccly]

Sounds good... in theory. Truth is we don't know this, their mail client is proprietary and even if it was open source we still wouldn't know what their servers are logging. I am in a similar situation and I trust Google more than ProtonMail with all that Tesonet data weirdness pointing back to one guy. These shell companies can go and disappear overnight, something to consider.

[wildduck]

Protonmail's email encrypted in the browser! Their client is open source:

https://github.com/ProtonMail/WebClient

It is main reason to use ProtonMail over Gmail.