How to block email tracking
Some marketing, sales and recruiting emails contain small remote images used to record a request. Mailshade uses Chrome's declarativeNetRequest API to cancel receiver-side browser requests that match a reviewed tracker-pixel endpoint catalog across six opt-in web clients: Gmail, Outlook, Office 365, Superhuman, Yahoo Mail and ProtonMail. DOM scanning separately detects pixels and supported tracking links in opened messages; for a recognized redirect, Mailshade lets you choose the direct destination or original URL. A local per-sender dashboard records detected tracker occurrences. In Gmail, browser-side cancellation of supported proxy URL forms does not establish whether Google fetched or cached the remote image earlier. This guide explains the tested scope and how to verify a browser request outcome.
What Mailshade handles
Two mechanisms: open-tracking pixels, which are remote images used to record a request, and click-tracking redirects, which route through an intermediary before the destination. DNR cancels browser requests matching Mailshade's reviewed tracker-pixel endpoint catalog. For a locally detected tracking link, you choose the direct destination or keep the original URL.
Steps to block email tracking
- Install Mailshade from mailshade.org and opt into the mail clients you use.
- Open Gmail, Outlook, Office 365, Superhuman, Yahoo Mail or ProtonMail.
- Open a controlled test message; browser requests matching reviewed tracker-pixel endpoints are cancelled via DNR.
- Check the red-eye overlay to see what the DOM scan detected.
- Open the dashboard to review sender-level detection history.
Blocking and detection are separate
DNR request outcomes and local DOM detections are separate evidence. A detection record does not by itself prove network cancellation, and a cancelled receiver-side browser request does not establish all upstream or sender-side state.
Confirming it works
Use Chrome DevTools or a controlled test message to verify that a matching browser request is cancelled. For Gmail, verify the supported proxy URL form and remember that Google may have fetched or cached the remote image before the receiver-side Chrome request. The dashboard is detection history, not network proof.
FAQ
Does blocking email tracking work in clients other than Gmail?
Yes. After you opt into each client, Mailshade cancels browser requests matching its reviewed tracker-pixel endpoint catalog across Gmail, Outlook, Office 365, Superhuman, Yahoo Mail and ProtonMail.
Will blocking trackers break the images in legitimate emails?
Mailshade targets reviewed tracker-pixel endpoints rather than disabling all images. Non-matching images can continue to load.
What does a cancelled browser request establish?
It establishes that the tested receiver-side browser request did not complete from the page. It does not establish all upstream or sender-side state; in Gmail, Google may have fetched or cached the remote image earlier.
Is any of my email data sent to a server when blocking?
Core inbox history is not sent to Mailshade servers. Tracker events stay in local IndexedDB with sender and opaque message context, and full tracker URLs are reduced to origins. Settings can use Chrome Sync; paid actions contact Mailshade auth/Polar, and optional privacy-filtered Hawk crash reports are off by default.
How much does Mailshade cost?
Core protection remains free after a 14-day Pro trial, with rolling seven-day history and a top-10 sender view. Paid Pro adds full history, top 30 senders and CSV export, starting at $3.99 per month or $19 one-time.