Efter restore af mailbox er postkassen tom

hvad er det for en exchange: 5,5 eller 2000?
hvad er det for backup program du har brugt.?

Restore a Mailbox by Using Exchange System Manager
To restore a mailbox by using Exchange System Manager, follow these steps:
Click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
Expand Administrative Groups, and then expand AdministrativeGroupName.
Expand Servers, and then expand ServerName.
Right-click Mailbox Store, and then click Run Cleanup Agent.
Right-click the mailbox that you want to recover, and then click Reconnect.
In the list of Active Directory accounts that appear, click the user account to which you want the mailbox to connect, and then click OK.
Quit Exchange System Manager.

http://support.microsoft.com/default.aspx?scid=kb;en-us;146920
Her er et par tips, som du måske kan bruge :0)