Ask HN: How do some email clients track 'who read' the email?
This is puzzling me.
Even if there are multiple receivers, `to`, `cc`, `bcc` there are some companies that in their client tell you exactly who opened it.
How is it implemented? I always assume these trackers use some hidden pixel image when sending emails - but how can they trace the exact person who opened the email?
Even if there are multiple receivers, `to`, `cc`, `bcc` there are some companies that in their client tell you exactly who opened it.
How is it implemented? I always assume these trackers use some hidden pixel image when sending emails - but how can they trace the exact person who opened the email?