Emails can sometimes contain very detailed and very denoting user information. Trying to differentiate between users "personal information" and users "personal content" is imho a rather dangerous thing to do because who decides where to draw the lines between the two?
As a user, I expect my data, regardless of which data, to stay private unless I explicitly intent to publish it to the public or somebody else. I most certainly do not expect some employees reading through my private emails for their lunch-break entertainment.
That's a complete strawman argument that has nothing to do with what I wrote. The distinction is correct and factual in this exact situation. You are attempting to redefine terms for apparently no reason other than to argue.
Whether emails contain detailed information or not is irrelevant to the term "user information" in this context, meaning information about a user. The discussion is about whether an email service requires personal information to operate.
> As a user, I expect my data, regardless of which data, to stay private unless I explicitly intent to publish it to the public or somebody else. I most certainly do not expect some employees reading through my private emails for their lunch-break entertainment.
In the real-world, you either need to change your expectations or encrypt your data.