[halflings]

> It does not need to read the body of email in order to work. It can index just the header(to, date, subject) The header is still personal data. Using the header but avoiding the body does not make much sense.

Again, "reading" emails seems to be an arbitrary distinction. Your emails are stored and served to you, so they are read by HTTP servers, by your browser, by many things. The real issue is the use that is made of those readers: an index that allows you to search your emails more efficiently does not seem to be nefarious, but I definitely agree that other nefarious uses are possible (say some company that would use emails to target people in debt or something like that), just not the case with Gmail.

> You can use a program on your computer locally to keep your emails and index&search them.

Right, but then it's not Gmail anymore, that's just an IMAP mail server with Thunderbird. Gmail started as a smart webmail; being able to quickly search your emails from anywhere, without a desktop client, without fetching thousands of emails before you could perform a search.