There are only small stories of cooperation with the authorities and leaked client information to the press, financial assistance to CIA employees, and support for the political will of the G7. There are no documents or investigations. In any case, email is not a tool to expect privacy and anonymity. At most, email is a trash can for spam and mailings. 

 But I get better security if the CIA is reading my emails! In Switzerland! 

 CIA is the least of the threats for me 😅 Also all Proton services are very cheap, that's why I use their VPN to watch porn. I certainly wouldn't use Proton for anything else 😂