Called PSS today due to an issue with a mailbox import refusing to work.
[PS] C:\temp>Import-Mailbox -identity test-pstfolderpath c:\temp\test123.pst
Error was found for swinc (email@example.com) because: Error occurred in the step: Approving object. An unknown error
has occurred., error code: -2147221219
StatusCode : -2147221219
StatusMessage : Error occurred in the step: Approving object. An unknown error has occurred.
When you run an Exchange Best Practices Analyzer (BPA) and it warns on this, you should fix it. Even though the instructions mention storage groups and are clearly based on Exchange 2007. I asked the technician about this and he stated that the Exchange 2010 specific fix is not yet published, but was in their internal KB still. The same fix describe in this BPA result will also address the import-mailbox error shown above.
This links you to:
Copy the distinguished name attribute of a mailbox database on the server
Paste this value into the homemdb attribute of the System Attendant object in AD (which installs blank by default)
Restart the Exchange Information Store service
Restart the Exchange System Attendant service
Run Import-mailbox again