John,
Emails are stored in two locations:
- Global Repository - this is what you see when you log in as admin
- User Repository - this exists when Xeams is either used in Hybrid or Stand alone mode. IMAP/POP3 repositories are fetched from here. When you delete emails they are removed from here.
Therefore, you should be able to restore email from the Global Repository. Log in as 'admin', go to Message Repository, search for the desired message using the sender's email address. Once found, restore it.