Click any unified folder, rightclick and select properties and then click 'choose' to UNtick any such folders I presume you noticed that Postbox is no more, after 12/31.

Hi @David, thank you for your response, but this is not what I need. In Thunderbird, I want to see the account list at the top, similar to how it is in Postbox. Below this list, I want to display only the folders for the selected account, not the folders of other accounts. If I choose a different account, the folders for the newly selected account should appear instead.

I know that Postbox has been sold, which is why I’m trying to configure Thunderbird to behave like Postbox.

If you want accounts listed individually, you can select view>folders and tick 'all folders' - and you can also UNtick unified folders. I have used Postbox and there is no way for an identical setup - close but not identical.