After creating a new mailbox database in Exchange 2010, the database creation was successful, however it failed when trying to mount it. I was presented with the following error:

MapiExceptionNotFound: Unable to mount database. (hr=0x8004010f, ec=-2147221233)

Apparently, this can happen if the value of the ConfigurationDomainController parameter and the value of the PreferredGlobalCatalog parameter are different. –

To resolve this you can set the preferred Active Directory server in the Exchange Management Shell:

Set-ADServerSettings –PreferredServer <DC FQDN>