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. That leaves Outlook and Office 365 users without an easy fix. Mailshade is one of the few blockers that treats Outlook web as a first-class client: it runs on outlook.live.com and outlook.office.com and uses Chrome's declarativeNetRequest to cancel known tracker requests at the network layer before they fire, so the open never reaches the sender. It also unwraps click-tracking redirect links and records each blocked sender in a local dashboard. This guide explains why Outlook coverage is rare, how to block pixels in both consumer Outlook and Office 365, and how to confirm it is working 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 from mailshade.org.
- Open Outlook on the web at outlook.live.com, or Office 365 at outlook.office.com.
- Open a tracked message — the pixel request is cancelled via DNR before it loads.
- Check the red-eye overlay for the blocked tracker domain.
Consumer Outlook vs Office 365
Mailshade covers both the consumer Outlook web client and the Office 365 enterprise webmail. The blocking mechanism is identical: declarativeNetRequest rules cancel the tracker request regardless of which Outlook surface you use.
Keep your images
Only known tracker domains are blocked, so logos, signatures and newsletter images still render. You do not need to turn off images in Outlook settings.
FAQ
Do most tracker blockers work in Outlook?
No. Most are Gmail-only. Mailshade is one of the few that covers Outlook web and Office 365, blocking tracker pixels there via declarativeNetRequest just as it does in Gmail.
Does this cover both Outlook.com and Office 365?
Yes. Mailshade runs on outlook.live.com (consumer Outlook) and outlook.office.com (Office 365), using the same network-level blocking on both surfaces.
Does it work in the Outlook desktop application?
No. Mailshade is a Chrome MV3 extension for web clients. It blocks tracking in Outlook on the web, not in the native Outlook desktop app, which does not support browser extensions.
Will blocking pixels stop legitimate Outlook images loading?
No. Mailshade blocks only known tracker domains, so signatures, logos and newsletter images load normally. Transactional and internal email is unaffected.
How much does Mailshade cost?
Paid plans start at $3.99 per month or $19 one-time for the Founders Lifetime tier. Pricing is the same for every supported client and is listed at mailshade.org.