You can read your email from the Inbox or any other folder within each individual account. Tap a message entry to open it.
If you enable the Auto-rotate screen setting (in the Display menu) and the Split view setting (in the Email settings), the Email app is displayed in a split-screen format when the phone is held horizontally. Your Inbox is displayed on the left side of the screen. Tap an email to open and display its contents on the right side of the screen.