I was having problems with One email. It would crash Entourage when I tried to view it. I was then asked to rebuild Entourage.

After one attempt, I have lost 95% of the old email I had, and 100% of the email in my inbox.

I have gone through the Microsoft Users, and looked at all my old Database and Database Cache, and it is gone.

There has to be a way to rerieve it.

Please advise.
Is there any particular reason that you are using Entourage? If you scan this forum, you find that this Microsoft POS gives problems for lots of users. Just because it is big and bloated and difficult to navigate doesn't mean that it is any good. Try MacOS X Mail, Thunderbird, Eudora, or any of a number of alternatives. You may find that you enjoy your computing experience a lot more when you spend less time troubleshooting badly conceived and and implemented apps like Entourage.