My iCloud mail inbox has been emptied
My iCloud mail inbox is suddenly empty. I have tried restoring it with no success.
My folders still contain emails, it is just my inbox.
Please help me get my emails back.
See the article Rebuild mailboxes in Mail on Mac - Apple Support
If emails appear to be missing in Mail on Mac - Apple Support
If you set up Time Machine to back up files on your Mac, you can use the backups to restore content that Mail downloaded (based on options set in Mail and on your Mac). See Restore items backed up with Time Machine.
Make sure you have not enabled hidden filter Filter emails in Mail on Mac - Apple Support
Or hidden the side bar Use the sidebar in Mail on Mac - Apple Support
Click on the icon shown with arrow to view all mails , drop down arrow to see the iCloud account ( when its activated from apple mail application it will mirror from iCloud.com ) also .
Note : if POP mail account is used it depends on your internet service provider to save mails on server for how many years .