Outlook for Mac update removes email conversation history

At a glance:

• Outlook for Mac version 16.110 (build 26061317) released on June 16 stops showing original messages when replying or forwarding.
• The only known fix is to roll back to version 16.109.3 or earlier and disable automatic updates.
• No official timeline has been given for a Microsoft‑issued patch, leaving enterprise‑managed devices in limbo.

What happened

Microsoft rolled out Outlook for Mac version 16.110 (build 26061317) on June 16. The update unintentionally removed the default behaviour of inserting the original email thread into the reply or forward window. Previously, users could see the full conversation context when composing a response, a feature that many rely on for clarity and record‑keeping.

The issue was first reported by users on Microsoft Learn, the company’s official documentation and learning platform, and subsequently covered by The Register. A Microsoft representative confirmed the regression but did not provide an immediate comment on a fix. The bug affects all Mac installations that have automatically updated to the new version, regardless of whether the client is part of a personal or corporate deployment.

How it affects users

For individual users, the loss of conversation history means each reply appears as a blank canvas, forcing them to manually copy‑paste prior messages or risk sending incomplete context. This can lead to miscommunication, especially in threaded discussions where prior remarks are essential for understanding.

Enterprise users face a larger problem: many organisations enforce automatic updates via Microsoft Auto‑Update (MAU). When the bug appears on devices managed by an employer, IT departments must either wait for a Microsoft‑issued remediation or intervene manually. The latter involves uninstalling the problematic version, reinstalling an older build, and then disabling automatic updates—a process that can be time‑consuming at scale.

Workaround and steps to revert

Microsoft’s temporary workaround is to downgrade to Outlook for Mac version 16.109.3 or any earlier build. The process is as follows:

1. Open the Help menu in Outlook and select Check for Updates.
2. Uncheck the box labeled Automatically keep Microsoft apps up to date.
3. Uninstall the current Outlook version 16.110.
4. Download the installer for version 16.109.3 (or an earlier release) from Microsoft’s download archive.
5. Install the older version and verify that reply and forward windows now include the original message thread.

After the bug is resolved in a future update, users should return to the Check for Updates dialog and re‑enable automatic updates to stay current with security patches and feature releases.

Potential impact and next steps

The conversation‑history regression touches a core usability expectation for email clients, so it may generate a spike in support tickets and negative sentiment on community forums. If Microsoft does not address the issue promptly, competitors such as Apple Mail or third‑party clients could see a modest uptick in adoption among power users seeking a more reliable experience.

From a business perspective, the incident underscores the risk of aggressive auto‑update policies on critical productivity tools. Enterprises may reconsider how they stage updates—opting for staged rollouts or pilot groups before full deployment—to catch regressions early. Microsoft has not announced a timeline for a permanent fix, but the company typically prioritises bugs that break fundamental workflows, so a patch can be expected in the coming weeks.