I have two iPhone 5s. On one of them the Mail App works perfectly with Verizon.net with no issues. On the other hand, the other iPhone 5 has had continual issues with email using Verizon.net. Big time data useage (even on Wifi) and inability to receive and send messages. After talking with multiple customer service reps including corporate, I have been advised by a Tech Manager that this is a known issue with the iPhone and is an Apple software problem which should be fixed in the future. I have been advised to use the FIOS app to check my email. Has anyone out there experienced this issue?