Rated 5 out of 5 stars

I do not use this as intended, but it works great for my needs.

I use "View/Layout/Vertical".

I show all my inboxes as Quick-Folders, renamed to the account names.

I am using the appearance "Toolbar Buttons", so it looks like build in.
I enlarged the names of the folders and the folder area to 20/34px.

Via "View/Layout/Folder Pane" I hide the default folder pane.

The main reason for all this is, that I do not want to see the count of unread messages in my inbox and all of its sub folders, I only want to see the count of unread messages for the inbox itself.

The side effect is, that I have a very simple and clean interface now.

On the left side the subjects, on the right side the message and on the top the Quick-Folders.

This review is for a previous version of the add-on (4.1.1).