Did you do a software update on your iPhone? Try holding both power and home buttons for 10 seconds to reboot your iPhone.
Then go into settings ---->>>> mail, contact and calendar, then remove your email account and reinstall it, and see if that helps.
I did that and it did not fix the problem. I did do a software update this morning, but this problem was before that. I did setup an icloud account because I just bought an ipad.
The best option is to restore your phone as it seems your mail software has become corrupted.
•Attach the phone to the pc
•Turn the phone off
•Press and hold power. Keep holding power. As soon as you see display on the screen of any sort press and hold home.
•Hold power and home together for *exactly* 10 seconds.
•Release power but keep holding home until the pc beeps as a USB device is recognized.
•At this point the display will come on. Now your restore should work.
After you finished all those steps, open iTunes and click yes when they asked if you want to restore. Let me know if you still have problems after you have restored it.
I have never plugged my phone into my pc.
So you have never synced or backed up your iPhone with iTunes? Doing a restore will erase all data on your iPhone. If you have any important data on your iPhone you want to keep, it is not recommended to do a restore before you back up your iPhone with iTunes.