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The vertical and compact layouts are similar and show the panels, from left to right:
On the mobile version there's a selector on the toolbar to tap < Folders to select and see the folder view. Select Sent objects.
On the mobile app there's a menu icon on the header to tap to select and see the folder view. Select Sent objects.
Hi metalmanal, it looks like Gondola has hit the nail on the head with that last post. Please post back to let us know if you're sorted.