Microsoft Outlook on Mac - Cannot revert back to Legacy mode

Jay Betito 40 Reputation points
2025-09-02T17:03:44.2233333+00:00

Hi Support!

I'm assisting a user of mine who is having an issue of being unable to revert back to Legacy mode for Outlook. This is on Outlook for Mac. Upon selecting to revert, the app will restart but remain in New Mode. We have tried a restart of the system, and clearing the application data/experimental features to no resolve. The Microsoft Updater is currently set to Beta channel.

-Jay

Outlook | MacOS | Legacy Outlook for Mac | For business
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  1. Wu 10 Reputation points
    2025-09-03T08:21:20.3866667+00:00

    I also have the same problem.

    Today when I open my outlook it switch from legacy to new interface.

    After I selected the legacy option under help menu, outlook reopened but still under new interface. It doesn't switch back to the legacy model.

    The reason why I can't switch to the new interface is because many of my old emails can't be accessed under the new version. my folders and everything are not the same as under legacy interface.

    Please help!!! I can't do my work!

    I m on

    Licence: Microsoft 365 Subscription

    Version 16.102 (25083120)

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  2. Catherine Ames 0 Reputation points
    2025-09-03T18:52:28.2233333+00:00

    Same problem. I cannot revert to legacy and my old emails and new groups have dissappeared. I cannot get them back. How to get back to Legacy?

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  3. Daniel Pratl 0 Reputation points
    2025-09-05T09:27:14.1966667+00:00

    I'm facing the same Problem. Switch to Legay Outlook just causes to restart the new one. This should only happening after October :(

    There are several functions we need from the legacy Outlook to operate (mostly searching in m365 Group Calendars)

    Using m365 Business Standard License.

    Moving from Update to stable didn't solve the problem.

    Thanks


  4. Roger 25 Reputation points
    2025-09-06T04:43:29.32+00:00

    I have the same issue. The New Outlook has lost several functionality aspects from the Classic Outlook (search items, displaying who the message is 'to' in the list display, etc) and I wish to keep using to Classic environment.

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  5. Paul McMahon 0 Reputation points
    2025-10-27T02:46:07.8466667+00:00

    The problems are a) with the loss of folders set up using email rules previously. This is lost in the upgrade away from legacy outlook settings and there does not seem to be a path forward in the new version for business users who need to keep emails and b) having to re-enter all of the account settings including passwords after the upgrade away from legacy outlook. The Microsoft support staff are polite and try to help but are not aware of how the upgrade affects users. Trying to explain that you are being asked to re-enter passwords by the desktop app does not seem to register with support staff. The integration with Microsoft teams seems to fail spectacularly after the upgrade away from legacy outlook. So there’re seems to be a loss of integration functionality after the upgrade.

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