Cannot Get Mail - The connection to the server failed
I have an iPhone 4S and iPad 1 which have suddenly stopped iCloud email. Error message is "Cannot get Mail - The connection to the server failed". I have the same settings as my partner who has an iPhone 5 and iPad 1 which are functioning correctly. We are all on up to date software versions. I use a different Apple ID but we both use an windows PC as host.
iPhone 4S, iOS 6.1.3