iOS 26 gave mail app non-adjustable split screen
Since iOS 26 update, my mail app has split screen that has no bar to slide to close right screen preview. How to get rid of permanently?
iPad, iPadOS 26
How to Disable Split Screen in iPadOS 26
Open the Settings app.
Scroll down and tap Multitasking & Gestures.
Under the Multitasking options, you will likely see a choice between Full Screen Apps, Windowed Apps, and possibly Stage Manager.
Select Full Screen Apps.