Microsoft to retire Copilot’s Prioritize My Inbox in Outlook from October 26

Key Points

1. Microsoft is retiring Outlook's Copilot-powered Prioritize My Inbox feature, with rollback starting October 26, 2026.
2. The AI tool surfaced the emails judged most relevant to each user's workflow across Outlook clients.
3. Removal ends a feature Microsoft promoted little more than a year ago as transformative for email.

The latest:

Outlook’s Prioritize My Inbox, the Copilot feature that ranked incoming mail by relevance to each user, is being switched off. Microsoft said the retirement begins October 26, 2026 and will proceed gradually until the tool is fully removed by the end of March 2027. The company described the move as part of a cleanup effort covering all Outlook clients, according to Windows Central.

Details:

• The feature: Prioritize My Inbox used Copilot to read an inbox and push forward the messages it judged most relevant to a user’s workflow, rather than ordering mail strictly by arrival time. It was positioned for users receiving more email than they could realistically triage manually.
• The timeline: The rollback starts October 26, 2026 and runs in stages, with Microsoft saying the feature will be gone entirely by the end of March 2027. That five-month window means affected users will lose access at different points rather than all at once.
• The reason given: Microsoft attributed the removal to a “cleanup effort” rather than to any performance or reliability problem with the tool. No usage figures, cost rationale or user-feedback data were cited in support of the decision.
• How it was announced: The change was communicated through the Microsoft 365 Message Center, the admin-facing channel the company uses to notify IT administrators of service changes, rather than through a public blog post or consumer-facing announcement.
• The scope: The retirement applies to all Outlook clients, according to Windows Central, meaning there is no platform where the feature survives. Microsoft did not name a replacement tool or point users to an alternative Copilot capability for inbox triage.
• The reversal: Microsoft promoted the feature just over a year ago, framing it as a significant change to how email is handled. Its withdrawal comes without the company publicly revisiting that earlier framing.
• What is unstated: Microsoft did not say whether Prioritize My Inbox functionality will reappear inside another Copilot surface, nor whether any prioritization settings or user data tied to the feature will be preserved after the rollback completes.

Background:

Copilot is Microsoft’s AI assistant layer built across Microsoft 365 apps, including Outlook. Inbox prioritization was among the email-specific capabilities the company added as it pushed Copilot features into everyday Office workflows.

Between the lines:

Retiring a feature through the Message Center under a cleanup label, without a named replacement or any usage data, suggests a quiet consolidation rather than a response to a specific failure. The five-month staged timeline and the absence of a successor tool leave open whether inbox prioritization returns in another Copilot form or disappears from Outlook entirely.

What’s next

Watch for the first clients to lose the feature after October 26, for any Message Center follow-up naming a replacement, and for confirmation that the rollback completes on schedule by the end of March 2027.