Iphone 5C email issues

I purchased my wife a new 5C (upgarded from the 4) and she is having continuous issues with email downloading. Sometimes it downloads, others it sayd it cant download from the server.. she had 3 email accounts. I have a Iphone 5 with similar accounts and no issues. She never had this problem with the Iphone 4. We turn it off and back on and sometimes that works but it seems like there is an issue with the mail routine of the 5C. Anyone else know about this?