As many others I’m using Gmail as an email provider. And now I’m quite sure that email content scanning is happening there.
It’s just the question how intense this is done and what is happening after the scanning?
I assume that at least sometimes data of the users is given further to other companies and these companies can then address the users directly.
So it is definitely recommended to use other solutions for a real private conversation, e. g. using another service or use end to end encryption like flowcrypt for chrome.
Google claims they don’t read your email, but I have strong doubts that this is completely true.
I don’t wanna go into the private details, but I wrote just recently some specific phrases and was addressed by an email the day after directly related to that topic. And the email did not go into the spam folder…