First, ensure that you have updated to the most recent version of iPadOS - currently iPadOS 14.8 or iPadOS 15.0.2.
If the iPad is already running one of these two versions, force close the Mail App - and then force-restart your iPad.
To force close an App, swipe-upwards from the bottom edge of the screen to the centre - and pause briefly before lifting your finger from the screen; the Task Switcher will open, showing thumbnail images for each App. Swipe the Mail App off the top of the screen.
Next, force-restart the iPad:
- On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
- On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.
