Who tracks when you open an email
Almost every marketing email contains an invisible image one pixel in size. When you open the email, your mail app loads it from the sender’s server — and the sender learns that the email was read, when, on which device and roughly where. Your email address is often embedded in the address of that image.
Here you can check any email: which platform sent it, whether it contains open-tracking pixels, whose they are, and whether the email tracks which links you click.
The file never leaves your browser. The email is analysed right on this page and its images are not loaded — the check itself does not “open” the email.
or drag it here — an .eml file
The file stays in your browser — it is never sent anywhere, and the email’s images are not loaded.
How to save an email as an .eml file
- Gmail: open the email → ⋮ → “Show original” → “Download original”.
- Proton Mail: open the email → ⋯ (More) → “Export”.
- Thunderbird: “File → Save As → File”.
- Apple Mail: “File → Save As…”, format “Raw Message Source”.
- Other mail services: look for “Show original”, “Download message” or “Save as .eml”.
What the result means
- Sent with — the mailing platform the shop or service used to send the email. Technical headers and DKIM signatures give it away.
- Open-tracking pixels — invisible counter images. If the image address contains a unique number, the open is tied to you personally.
- Your address in links — whether your email address appears in image and link addresses: in plain text, in base64 or as a hash.
- Click tracking — links that do not go straight to the site but through a counting server.
A pixel only fires if your mail app loads images. Some mail services, such as Proton Mail, block known trackers, and Gmail loads images through its own server — the sender then does not see your IP, but still learns that the email was opened.