Proton Mail says that the new Outlook app for Windows is Microsoft's new data collection service

Good call. Here's a snapshot of scroogled.com in 2013 from the wayback machine.

Google goes through every Gmail that's sent or received, looking for keywords so they can target Gmail users with paid ads. And there's no way to opt out of this invasion of your privacy. Outlook.com is different—we don't go through your email to sell ads.