You are very welcome. I’m delighted that the Mail toolbar issue is resolved.
Email messages can viewed as full screen should you choose to do so.
To view an email full-screen, first find the email message that you wish to view in mailbox list of email messages, then:
- Touch-and-hold (i.e., a long touch) the message that you wish to see full screen; an Action Menu will appear.
- From the menu, tap Open in New Window; this will open your chosen mail message in its own window.
- At top-centre of the window, you will see the multitasking trigger button “…”; tap the button
- Tap the Full Screen button; the current viewing window will transform to a full screen view:
More information about multi-tasking features of iPadOS can be found in this support page:
Use multitasking on your iPad - Apple Support
The iPad User Guide is also a rich source of information about using iPad and its many features. The Guide is available both online using a web browser (such as Safari), or as an Apple Books download:
iPad User Guide - Apple Support
https://books.apple.com/book/id1567104892