When making a PowerShell query which includes an attribute starting with "edsva-MsExch-", such as the edsva-MsExch-MailboxDatabasesConfigID virtual attribute, a null value is returned. When viewing the object in the Advanced Properties through the Active Roles Console, there is a value in that attribute.
In addition, in the Active Roles Console, when using Find | Advanced and specifying a Field, there are no results for any attribute starting with "edsva-MsExch-".
This is expected functionality.
These attributes are not stored in the Active Roles configuration database and are not stored in Active Directory.
Instead, they are calculated in real-time.
These and any other calculated attributes cannot be queried in the Advanced Find, and cannot be queried in the live environment via PowerShell.
However, if PowerShell is used to store these attributes onto a local PowerShell variable, we can then query the attributes stored on the variable and retrieve the desired results.
These sample PowerShell cmdlets achieve this:
$Mbox = Get-QADObject "TestUser" -IncludeAllProperties -proxy | Select 'edsva-MsExch-MailboxDatabasesConfigID'