On my iPhone mail (IOS) all IO see are the messages without sidebar, yet on my iPad in Landscape I have a sidebar, which disappears if I rotate the iPad, my question is how do I hide the sidebar when viewing landscape on iPad?
There is no setting for that in the mail app on iPad. So you can't.
There is no setting for that in the mail app on iPad. So you can't.
This is not possible in landscape mode using the standard iOS Mail app.
If you want the capability to do this look at third party email clients for iOS.
I use Edison Mail and it has the feature you are looking for.
Email - Edison Mail by Edison Software Inc.
https://apps.apple.com/us/app/email-edison-mail/id922793622
Hide Sidebar in IOS mail
