what email software are you using?
something like Outlook or Thunderbird?
or online via a browser like Gmail or Hotmail?
but if you deleted stuff, generally they go to the Deleted Items folders of whatever software you are using (not the Recycle Bin of the PC).
if the Deleted Items folder is also empty, you will be needing those backups you regularly do of your PC to restore them from.
[sarcasm] you know, those backups you only did yesterday! [/sarcasm]