Ok, this was a weird one. Trying to send email with iPhone 4 and was getting the error "No password" for the email account. Double, triple checked the password and decided a reboot might fix it. Rebooted the iPhone and when it came back up ALL email accounts were gone. 3 IMAP accounts, 1 Exchange account and 1 POP account, all gone. I've never seen that type of weirdness before and hopefully that won't happen again. Very odd.