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macbook freezes up when responding to certain emails in outlook, CPU goes to max with fans blowing

Adriaan Doets 0 Reputation points
2025-09-27T10:00:22.0233333+00:00

Hello,

I am experiencing a complete freeze of my MacBook with DOM >2023, with CPU speed to max, with fans blowing at max speed when responding to certain e-mails in Outlook. I have removed all add-ins already.

Outlook has been reloaded, but the results remain the same.

Do you have any suggestions what the cause could be?

Thank you

Adriaan

Outlook | MacOS | New Outlook for Mac | For home

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  1. IGYQ 16,715 Reputation points Independent Advisor
    2025-09-27T10:42:51.5666667+00:00

    Hi,

    This issue pops up a lot with Outlook on macOS. It happens especially in the newer versions. You already reinstalled the app and got rid of add-ins. So the freezing with CPU spiking high is probably from trouble rendering email content. That could be heavy HTML stuff or emails that are messed up somehow. Or maybe the profile or database got corrupted underneath. Here are some main steps you can take to sort it out.

    First off check those emails that cause problems. The freezes tend to hit only when you reply to or forward specific ones. Emails loaded with complex HTML, big images right in the body, tables, or even CSS and JavaScript embedded can make Outlook's WebKit engine loop on the CPU. Try replying in plain text mode to test it. Just go to Format and pick Make Plain Text.

    Next rebuild the Outlook profile or database. Close the app completely. Head to this folder ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles. Back up your main profile folder first thing. Then make a fresh profile and add your accounts back in. If things work fine with the new one the old profile was likely corrupted.

    Also update your Office and macOS. Get the latest build for Microsoft 365 Outlook. These glitches often get patched in the monthly updates. Update macOS as well since improvements to WebKit rendering can help Outlook run better.

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