IT: Server encryption technology / prevent unauthorized file distribution?

So I work for an IT firm that's expanding and wishes to cover server encryption security. Our problem is that we do not want company users copying and/or emailing encrypted files. The thing is if a user works for the company, they have the ability to decrypt and access the files, but we do not want them to distribute any of the files unencrypted. Is it possible that any files moved off the company computers, either by usb or email, will become unreadable or encrypted?