How email open tracking quietly took over the web There are some 269 billion emails sent and received daily. That’s roughly 35 emails for every person on the planet, every day. Over 40 percent of those emails are tracked, according to a study published last June by OMC, an “email intelligence” company that also builds anti-tracking tools. But lately, a surprising – and growing – number of tracked emails are being sent not from corporations, but acquaintances. (Wired)