Collapse mailboxes to 1 line each with display of unread messages from the inbox

Is your feature request related to a problem? Please describe.

I have set up to 7 e-mail addresses as mailboxes, each with additional subfolders. Some folders can be collapsed, but Inbox, Favorites, Drafts, Sent and Trash cannot be collapsed. It would be great if the mailboxes could be fully collapsed. Because otherwise I always have to scroll down the left sidebar to see if there are any new messages.

Describe the solution you'd like

Each e-mail address set up can be collapsed to 1 line, each with a number showing the unread messages in the inbox. This would be extremely clear and helpful.

Describe alternatives you've considered

Collapse all mailboxes, but this still takes up too much space at the moment, as not everything can be collapsed and otherwise you can't see the unread inboxes.

Additional context

In addition, it would be great if the e-mail overview could be made a little more compact.

No file or test is named. Start by locating the left-sidebar mailbox rendering and the unread-message data used for inboxes; confirm how expanded and collapsed states are handled. Done means each mailbox can occupy one line with its inbox unread count visible, while the requested compact overview is addressed or explicitly scoped.