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Hide the Mailbox List/Sidebar
If you are using an iPad or your iPhone in landscape orientation, the "inbox" you might want to hide is the list of mailboxes (e.g., All Inboxes, specific accounts, Trash, etc.) that appears on the left side of the screen, taking up space from the message list.
- On iPhone in portrait mode, the Mailbox list usually disappears when you tap on an inbox to see the email messages. You return to it by tapping the Back arrow or "Mailboxes" link.
- On iPad (and sometimes iPhone in landscape), the mailbox list often stays as a sidebar. In some versions of iPadOS 26, users have reported that the sidebar is harder to collapse.
- Try dragging the divider between the mailboxes column and the message list column all the way to the left.
- Try double-tapping on a message to open it in a separate, full-screen window (though this is sometimes an alternative view, not a permanent change to the main app layout).
- Rotate your iPad to portrait orientation (if you were in landscape), as this may force the sidebar to collapse, depending on the current design.
