It depends on if you did a repair or format/reinstall.
If you did a repair, then it is possible that they are in a hidden, protected partition.
If you did a format and reinstall, then there is virtually no way that you can get it back, especially if you have restarted the computer.
I would call my ISP and tell them about what happened. If it is in a hidden partition, then they could tell you the exact location. As worse case, they may have your old E-mail on file, and they may send it back to you, but that is a long shot.
Sorry to be the barrer of bad news
We are all curious like a cat. We wonder, we ask, we learn.
Please post back when a suggestion works, so that others may learn.