How to block email tracking pixels
What an email tracking pixel is, what it tells the sender when you open a message, and how to block it: remote images, pixel removal and the trade-offs.
Sanjeev Maharjan5 min read
A tracking pixel is a tiny invisible image in an email. When your mail app loads it, the sender's server records that you opened the message, when, and from which network address. To block it, stop your mail app loading remote images, or use an app that removes the pixels before the email is shown. Either way the sender no longer learns that you opened it.
The short version: a pixel only works if your mail app fetches it. Set remote images to "ask first" and no pixel can report on you. An app that strips known pixel shapes lets you keep ordinary pictures for most mail. Tracked links are separate: they report when you press them.
What a tracking pixel is
An HTML email can contain pictures in two ways. Some are packed inside the message, like an attachment. Others are only an address: "fetch the picture from this server and show it here". Those are remote images, and your mail app has to contact the sender's server to get them.
A tracking pixel is a remote image made to be unseen: usually one pixel wide and tall, transparent, or hidden by the email's styling. Its address is different for every recipient, so a request for it tells the server exactly whose copy was opened. Most newsletter and marketing services add one by default.
What it tells the sender
| What the sender learns | Where it comes from |
|---|---|
| That your copy was opened, and that your address is in use | The image's address is unique to you |
| The time of each opening, and how many times | Each request is logged as it arrives |
| Your IP address, and from it your rough location and network provider | Every web request shows where it came from |
| Your mail app, and often your device | The details your app sends with the request |
A pixel cannot read your other mail, your contacts or your files. What it gives away is behaviour: you read this, at this time, in this place. For a newsletter that feeds an open rate. For a scammer it confirms a live address, one of the points in the guide on how to spot a phishing email.
How blocking works
Do not load remote images
If your mail app never contacts the sender's server, nothing is reported. This is the complete answer. Most mail apps have a setting worded as "load remote content" or "ask before showing images", with a button on each email to show its pictures.
Remove the pixels, keep the pictures
An app can look through the email before showing it and take out images shaped like a tracker: one pixel in size, zero in size, or hidden. Ordinary pictures still load, so the email looks as intended. This stops the common case but is not complete, because a logo with a unique address reports an opening as well as a pixel does.
Load images through a go-between
Some mail providers and apps fetch remote images through their own servers, so the sender sees the provider's address and not yours. That hides your location and device. The sender may still see that the image was fetched, and the go-between now knows which emails you opened.
The trade-offs
| Approach | What it stops | What it costs |
|---|---|---|
| Remote images off | Every image-based tracker | Emails look bare until you show the pictures |
| Pixel removal, images on | The usual invisible pixels | A tracker dressed as a normal image still loads |
| Images through a go-between | Your IP address, location and device | The opening may still be seen, and a third party is in the middle |
How to block tracking pixels, step by step
- Open your mail app's settings and find the privacy or viewing section.
- Find the remote images or remote content setting and choose "ask first", or the option that hides them.
- Open a newsletter to check: the pictures should be missing, with a button to show them.
- Show images only on mail where you do not mind the sender knowing.
- If you read the same account on a phone or in a browser, change the setting there too. It belongs to each app, not to the account.
Tracked links are a different thing
Blocking images does nothing about links. Many newsletters rewrite every link to pass through their own server, which records the press and sends you on. Nothing is reported until you press the link, so if you would rather not be counted, open the site yourself.
How Mailvie handles tracking pixels
Mailvie, a mail app for the Mac, removes invisible tracking images from every email before showing it: images one pixel or zero in size, and images hidden by styling. This happens on your Mac with fixed rules, no AI and no lookup service.
- Other remote images load by default, so email looks right when you open it. Settings, Privacy has "Ask first", which keeps them hidden until you press Show images.
- With images loading, a tracker made to look like an ordinary picture still gets through. "Ask first" is the setting that stops those.
- Email is shown with JavaScript off, so a message cannot run code to report on you.
- Mailvie does not fetch images through a server of ours: there is none. Remote images are on the published list of connections.
Tracker removal is free. You can download Mailvie for Mac (Apple Silicon, macOS 14 or later). To cut down the mail that carries trackers in the first place, see the guide on unsubscribing from emails in bulk on a Mac.
Questions people ask
Can a sender tell that I opened their email?
Only if your mail app loads a remote image from the message, or you press a tracked link. With remote images off, or the tracking image removed, reading an email sends nothing back to the sender.
Does blocking images stop link tracking?
No. A tracked link reports when you press it, whatever your image setting is. To avoid being counted, go to the site by typing its address or using a bookmark.
Will blocking remote images break my emails?
The text always remains, and pictures packed inside the message still show. Emails built mostly from remote pictures look empty until you choose to show the images for that message.
Can a tracking pixel give my computer a virus?
Not by itself. A pixel is an ordinary image request and carries no code. Its cost is to your privacy: it reveals the time, your rough location and your mail app.
Written by Sanjeev Maharjan
Sanjeev Maharjan builds Mailvie, a mail app for the Mac. Found a mistake in this guide? Write to [email protected].
