can't send e-mail after updating to ios 7.0.2
I upgraded my iphone 5 to IOS 7.0.2 and now I can't send e-mail. I can receive e-mail, but can't send. E-mails I try to send are in the outbox, and it says "Unable to send e-mail.....please go to Mail Account settings and enter a password". I've checked my mail account settings and re-entered my password, but it still won't send. I've tried rebooting, no help. Please reply with any ideas - Thanks
iPhone 5, iOS 7.0.2