My iphone 4s email stopped working?

My iphone email was working ever since I got it in august but suddenly it stopeed receiving emails, whenever I go to chick it just does the checking for mail and constant searching but never loads new messages though when I go on my computer there are plenty of new messages. Any ideas how to fix this problem? I have shut the phone off in hopes to reset the email but its still not working. I desperately need access to my email on the go, any ideas please help.thanks

Try logging out and back in on the iphones email if not try holding the home button while holding the power button a to do a quick reboot