It's kinda complicated, you know Betternet? They're a free VPN with no logging, however ad companies intercept traffic between you and Betternet and inject ads into it, so say they had a email scanner locally on decryption that scans and sells the contents of the email to ad parties to send you spam, or rather fingerprint your device and sell on your ad id.
Your emails are encrypted so nobody can read them but you, if police agencies try to gain access even protonmail themselves can't see your emails, and they're in Switzerland, which is strict on internet privacy so they're not selling your data for profit.
