Rebuild Folder -- Emails Are Gone



I was under the impression that "rebuilding" a folder optimized my files but did NOT delete them. However, after rebuilding a particular folder that I had created to save certain emails, all those emails are gone now.

I've tried reimporting the mbox from within the apple mail folder under the library directory, but it says the mbox is empty (there are no emails to be found).

Am I totally screwed or is there a way tofind these lost emails.

Thanks in advance