X-No-Archive The other day I was reading email in one of my free email accounts. Then I decided to compose an email to someone on my address list. When I clicked on that person's address, another window popped up, asking for my password. I found this unusual as I had just logged in. What really disturbed me was that the username was permanently entered in a username I'm not at all familiar with and the password box was empty, waiting for my password. I decided to play a game and used my password; remember--the username was different. I was able to get into my account and read all my emails although not compose or edit them. This told me that I was in a "read only" status under a different username. (I know the problem didn't have to do with my password as I had just changed my password a few days before.)
I had this same problem on three different occasions all with different usernames. I didn't follow through by entering my password but contacted the email company about the problem and they were evasive in their answer.
So I got to thinking and did some searching. What I found was that some free email companies can read your emails while you are reading them. It's their way of finding out how you do business; a sort of "phishing". As a result of this, I've decided that the free email account I was using is entitled to my business information as long as I keep the account open, but they aren't entitled to my personal emails. And I've transferred all my personal email addresses to my paid email account.
If you are a free email user, beware of this tactic. It may not be specifically mentioned nor obvious in the User Agreement, but it is in there and you need to read that agreement CAREFULLY.