Email tracker blocker for Office 365
Office 365 webmail loads remote tracking pixels like other clients, while consumer-focused blockers often skip the enterprise Outlook surface. After you opt into outlook.office.com, Mailshade uses Chrome's declarativeNetRequest to cancel requests to known tracker-pixel domains before they fire. A local DOM scan detects pixels and supported tracking-link patterns; recognized links offer a direct-or-original choice. Detected occurrences are recorded in a local per-sender dashboard. This page explains how known-domain blocking works in Office 365 webmail alongside the consumer Outlook client Mailshade also supports.
Office 365 and tracking
The Office 365 web client renders remote images, including tracking pixels, so opens can leak just as in other webmail.
What Mailshade does in Office 365
- After opt-in, cancels requests to known tracker-pixel domains via DNR on outlook.office.com.
- Detects supported tracking-link patterns locally and lets you choose direct or original.
- Shows a red-eye overlay naming the detected tracker domain.
- Records detected tracker occurrences in a per-sender IndexedDB dashboard.
Consumer Outlook too
Mailshade also offers separate opt-in coverage for consumer Outlook at outlook.live.com.
Local-first history
Core inbox history stays in local IndexedDB with tracker URLs reduced to origins; it is not transmitted to Mailshade servers. Settings can use Chrome Sync, paid actions contact Mailshade auth/Polar, and optional privacy-filtered Hawk crash reports are off by default.
FAQ
Does Office 365 block tracking pixels on its own?
Office 365 loads remote images including tracker pixels. Mailshade cancels requests to known tracker-pixel domains via declarativeNetRequest, so those requests send no open signal.
Does Mailshade cover both Office 365 and consumer Outlook?
Yes. After separate opt-in, it runs on outlook.office.com and outlook.live.com with the same known-domain DNR blocking.
Is my Office 365 mail data sent anywhere?
Core inbox history stays in local IndexedDB and is not sent to Mailshade servers. Settings can use Chrome Sync; paid actions contact Mailshade auth/Polar, and optional privacy-filtered Hawk crash reports are off by default.
Does it work in the Outlook desktop client used with Office 365?
No. Mailshade is a Chrome MV3 extension for the Office 365 web client at outlook.office.com. The native desktop Outlook does not support browser extensions.
How much does the Office 365 tracker blocker 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.