Hi @Heco
Welcome to our forum!
Currently, the folder sorting function is not supported in New Outlook.
Please understand that New Outlook is in preview, and many features have not yet been designed. For your experience, we recommend that you switch back to classic Outlook. Thanks for your feedback!
Also, I searched the official feedback portal and noticed a similar idea, the Outlook team has marked the item as ''We're considering this''. Please be patient and wait for the update of New Outlook. If you have any suggestions or ideas, it's suggested that you could post here. Hope Microsoft will notice this in the future. Thank you for your understanding and support!
Hope this helps!
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