How to determine how many mailbox licenses are used? (4247333)

During the migration of mailboxes, it is necessary to estimate the migration progress and see how many mailbox licenses have been used by Migration Manager for Exchange. Where can this information can be found?

I. Help | About dialog on the console:

1. Open Migration Manager and select Help | About.
2. Highlight the product on the Individual components window and click on the Details button which will open a license file.
3. The license file indicates information for both synchronized mailboxes and calendars. Actually, the license is not consumed when synchronizing only Calendar folders with Calendar agents (unifiedSync or legacy).

For Example:

Exchange 2X_ calendar mailboxes used N/A out of 200
Exchange 2X_ InterORg mailboxes used N/A out of 200

For Migration Manager for Exchange version 8.11 or earlier the license information can be also found:

II. In the registry on the server specified as the License server for Exchange migration. 

You can find out how many licenses have been used by Migration manager for Exchange version 8.12 or later, in the registry on the License server at HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Quest Software\Migration Manager for Exchange\TotalCounters\Exchange2x_InterOrgMailboxes. This registry key contains a full list of LegacyExchangeDN attributes of the mailboxes for which the license has been consumed.

Please note: License Reporter Utility is inapplicable to Migration Manager for Exchange version 8.12 or later.

For information on how licenses are counted please see:

Solution SOL44530 - How does Migration Manager for Exchange count licenses?
https://support.quest.com/migration-manager-for-exchange/kb/44530