By the MailGenerator Team · Updated November 8, 2026
Ever noticed that a company sends a "Still thinking about it?" email right after you opened their last one? That isn't a coincidence. Most marketing and sales emails contain invisible trackers that report back when, where and on what device you opened them. Here's how that works and how to switch most of it off.
What is a tracking pixel?
A tracking pixel is a tiny image, usually 1×1 pixel and transparent, embedded in an HTML email. The image isn't stored in the email itself. It sits on the sender's server, and each recipient gets a unique image address, something like tracker.example.com/open/8f3a2c.gif.
When your email app loads images, it requests that address. The sender's server logs the request and now knows:
- That you opened the email, and how many times
- When you opened it
- Your approximate location from your IP address (city or region, sometimes your company network)
- Your device and email app, from technical details sent with the request
No click is needed. Simply opening the message with images on is enough.
Tracked links
The second technique is link tracking. Instead of linking straight to shop.com/sale, the email links to something like click.mailer.com/r/8f3a2c?u=…, which records your click and then forwards you. That tells the sender exactly which link you clicked and confirms the email reached a real, active person.
Link tracking is harder to block than pixels, because blocking it breaks the link. You can usually spot it by hovering over the link before clicking: if the address shown is a long redirect on a different domain, it's tracked.
Who uses email tracking?
Almost every newsletter platform turns on open and click tracking by default. Online shops use it to time follow-ups. Sales tools tell salespeople the moment a prospect opens a pitch. And scammers use it too: a tracked open confirms that your address is live and worth targeting again. That's one reason the advice in our guide to stopping spam is never to open or reply to obvious junk.
How to block tracking pixels
Gmail
Gmail loads images through Google's own image proxy, which hides your IP address and location from the sender. However, the sender can still see that and when you opened the email. To stop that too:
- Open Gmail on the web and click the gear icon, then See all settings.
- On the General tab, find Images and choose Ask before displaying external images.
- Scroll down and click Save Changes. In the Gmail mobile app, the equivalent option is under the account's settings, in the images section.
You can still load images for a specific email with one click when you trust the sender.
Apple Mail
On iPhone, iPad and Mac, turn on Mail Privacy Protection. On iPhone it's in Settings → Mail (or Apps → Mail) → Privacy Protection. On a Mac, it's in Mail's Settings → Privacy. It loads remote content privately in the background for every email, which hides your IP address and makes open tracking unreliable for senders.
Outlook
The Outlook desktop app blocks external images by default for senders that aren't in your safe senders list. Keep that setting on and only download pictures for messages you trust. In Outlook on the web, review the privacy and external content options in Settings.
Other email apps
Look for a setting called "load remote images", "show external content" or "block remote content", and turn loading off. Privacy-focused providers such as Proton Mail and services like DuckDuckGo Email Protection also remove many known trackers automatically.
How to reduce link tracking
- Hover before you click to see where a link really goes.
- Visit the site directly instead of clicking the email link when you just want the sale or the article.
- Use a privacy-focused browser or extension; some strip common tracking parameters from links.
Does a temporary email stop tracking?
Partly. A temporary inbox means the sender's records are tied to a throwaway address instead of your real one, so their tracking data can't be linked to your identity or your other accounts. It doesn't stop the pixel itself from loading if images are shown, so the open is still recorded against that temporary address. For one-time sign-ups, that's usually exactly the trade-off you want: the sender learns nothing useful about you.
Is email tracking legal?
It depends on where you live. In the EU and UK, privacy regulators treat tracking pixels much like cookies, generally requiring consent. Canada's and the US's rules are looser, focusing on consent to receive marketing and on unsubscribe requirements rather than on tracking itself. Either way, the steps above work regardless of what the sender is allowed to do.
Frequently asked questions
Can someone tell if I opened an email from Gmail's preview?
If images load automatically, yes. With "Ask before displaying external images" turned on, they only know if you choose to load images.
Are read receipts the same thing?
No. A read receipt is a request built into some email systems that asks your permission to notify the sender. You can decline it. Tracking pixels don't ask.
Does blocking images break emails?
Marketing emails may look plain until you load images. Text, links and attachments still work normally.
