How to know if someone opened your email

Whether you are chasing a proposal, following up on outreach or checking that a newsletter landed, the same question comes up: did they actually open it? Email was never built to answer that. There is no reliable read receipt that works across Gmail, Outlook and Apple Mail, so what people call open tracking is really a clever workaround with real limits. Here is what it can honestly tell you, and what it cannot.

The trick is a single transparent image, one pixel wide, placed in the message with a unique address for each recipient. When the mail app loads that image, the request reaches the server and an open is recorded. That is the whole mechanism behind every "someone opened your email" notification you have ever seen.

It means an open is really "a mail app fetched an image". For years that was close enough to a human reading. It is not anymore. You can see the honest version of this on the email open tracking page.

Three things break the pixel. Apple Mail Privacy Protection, on since 2021, pre-loads that image for every Apple Mail recipient whether they read the message or not, so their open fires automatically. Gmail serves images through its own cache, which records a fetch of its own. And plenty of people block images entirely, so a real reader can leave no trace at all.

The result is that opens are inflated by machines on one side and hidden by image blocking on the other. A tool that shows you one flattering open rate is hiding this. directinapp separates likely-machine fetches from likely-human ones and labels the number an estimate. There is more on the Apple side of this in Apple Mail Privacy Protection and open rates.

A click is different. When someone taps a wrapped link in your email, that tap only happens because a person chose to act. A mail app does not tap your call to action on the reader’s behalf, and unlike the pixel, a wrapped link works even in a plain-text email where no image can load.

So the honest hierarchy is simple: treat a click as proof of engagement and an open as a rough direction. If you only trust one number, trust the click. See email click tracking for how that side works.

You do not need to move to a marketing platform to get this. Add the invisible pixel to your HTML email for a rough open signal, and replace your links with wrapped short links for the reliable click signal. Keep sending from Gmail, Outlook or whatever you use now; directinapp only measures, so your deliverability is untouched.

For outreach, invoices and proposals sent to a handful of people, this is often all you need. See email tracking without a marketing platform for that smaller-scale setup.

You can know, reliably, who clicked. You can get a rough, clearly-labelled sense of who opened. What you cannot get from any tool is a guaranteed "this person read every word", and anyone who promises that is overselling a pixel. Lead your follow-ups with clicks, use opens for direction, and you will be working with numbers that mean something.