Outlook on my MacBook

Hi @Jane, 

Thank you for posting your question in the Microsoft Q&A forum. 

I understand how frustrating this situation can be when you just want Outlook to work reliably on your Mac.  Based on your description, your Mac is running a Legacy version of Outlook, and the current Outlook app is not supported on your macOS version. Because of this, you must use Outlook on the web in Safari. 

The message You signed out of your account. It’s a good idea to close all browser windows usually appears when multiple Microsoft work or school accounts exist within the same Safari browser session. Safari does not reliably isolate Microsoft authentication tokens on older macOS versions, which leads to these conflicts. 

There are a few approaches that may help: 

-Try opening Outlook in a private or incognito window. This may temporarily isolate the session, but on Safari it does not always fully prevent Microsoft token reuse. 

-Remove any Microsoft-related credentials stored in your browser. This can prevent conflicts between accounts.  

-If the issue persists, you may need to manually remove cached authentication tokens. There is a helpful discussion on this method here: Cannot remove multiple Microsoft logged account from safari browser - Microsoft Q&A. 

For long-term stability on older macOS, the most reliable workaround is to use separate browsers for different accounts, since Legacy Outlook for Mac is no longer compatible with modern Microsoft 365 authentication. 

I hope this helps. 

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