The first time I ran CCleaner it did a great job of cleaning out unneeded files. However, it also cleaned out an email folder in which I had stored letters that I wanted to keep for later use. Those letteres are gone. Where did CCleaner put them? Are they recoverable?
Install and run Recuva to retrieve those files.
CC doesn't delete emails of any sort, either singly or the entire email folder - unless you've put the email folder in a temp directory, which you could say is pushing your luck a little.
Do as little on your pc as possible, download Recuva onto a flash or different partition, and run from there. I can't remember all the email folder extensions, I think OE is .dbx, so that's what you'll be looking for in OE, others will use different extensions.