i lost the mail folders where all accounts are consolidated
How do I restore my mail folders where all emails are consolidated?
MacBook Pro 15″, macOS 10.12
The "All whatever" folders can be added to the Favorites by clicking on the + button on the right side of the Favorites header. It will appear when you hover the cursor over it.
Then, select the folders you want to appear in Favorites from the popup menu in the dialog.