Missing e-mails in AT&T account
I went to search for important emails today and noticed that I have no e-mails after middle-October this year. I have verified this in Internet Explorer, Chrome, mobile phone, and other e-mail clients. Searching for known e-mail subject lines does not turn up the missing e-mails. Help?
EDIT: This is only for the INBOX. All other folders' email are intact still.