How to block tracking pixels in Outlook
Outlook on the web loads remote images, including the 1x1 tracking pixel that tells a sender you opened their message — and most tracker blockers ignore Outlook entirely, because they were built for Gmail. Mailshade treats Outlook web as a first-class, opt-in client: on outlook.live.com and outlook.office.com, Chrome's declarativeNetRequest cancels requests to known tracker-pixel domains before they fire, so those requests send no open signal. A local DOM scan detects pixels and known tracking-link patterns; recognized links offer a direct-or-original choice. The local dashboard records detected tracker occurrences. This guide explains how blocking works in both consumer Outlook and Office 365 without disabling images.
Why Outlook coverage is rare
Gmail dominates the tracker-blocker market, so most extensions only inject into mail.google.com. Outlook web uses different domains and markup, so blocking there takes deliberate support — which Trocker offers partially and Mailshade offers fully.
Blocking tracking pixels in Outlook
- Install Mailshade and opt into Outlook or Office 365.
- Open outlook.live.com or outlook.office.com.
- Open a tracked message — requests to known tracker-pixel domains are cancelled via DNR.
- Check the red-eye overlay for the tracker domain detected by the DOM scan.
Consumer Outlook vs Office 365
Mailshade covers both webmail surfaces. The blocking mechanism is identical: declarativeNetRequest rules cancel requests to known tracker-pixel domains regardless of which Outlook surface you use.
Keep your images
Only known tracker domains are blocked, so images from other domains continue to render. You do not need to turn off all images in Outlook settings.
FAQ
Do most tracker blockers work in Outlook?
Most are Gmail-only. After opt-in, Mailshade uses declarativeNetRequest to network-block known tracker-pixel domains in Outlook web and Office 365.
Does this cover both Outlook.com and Office 365?
Yes. Mailshade runs on outlook.live.com and outlook.office.com, using the same known-domain DNR blocking on both web surfaces after opt-in.
Does it work in the Outlook desktop application?
No. Mailshade is a Chrome MV3 extension for web clients. It network-blocks known tracker domains in Outlook web, not in the native desktop app.
Will blocking pixels stop legitimate Outlook images loading?
Mailshade blocks known tracker domains rather than all images, so images from other domains can continue to load.
How much does Mailshade cost?
Core protection remains free after a 14-day Pro trial. Paid Pro starts at $3.99 per month or $19 one-time for Founders Lifetime, with the same pricing across supported clients.