Have difficulty deleting iCloud e-mails. Have to delete 3-4 times.
iCloud e-mails keep coming back after being deleted. Have to delete them 3-4 times.
MacBook Pro (Retina, 15-inch, Mid 2014), iOS 9.1
Have you tried unchecking the Mail box in the iCloud Preference Pane? Don't panic when all your mail disappears. Rechecking Mail box will bring back all your mail and may reset things so it works correctly.