Today this just started with my iPhone 5 that I've had for two days now. Emails download in duplicate. I've checked settings, but am not sure what happened because it worked fine the previous two days.
Also very strange, when I enter Mail, Contacts, Calendars in Settings and click on the various accounts, e.g., POP Account, iCloud, Backup Email, it will not allow me to swipe the on/off button to turn off.
What's going on? Any help will be greatly appreciated.
View the Correct Answer Duplicate email messages in iPhone Support , iPhone Mail, Contact , Calendar errors Correct Answer