The Service File Viewer does not show any outstanding files waiting to be written the the target mailboxes, and the mail source agent is not processing any more mail items, but "Last PST flag found" is not being written to the Mail Target Agent log for synchronized mailboxes.
If the mailbox collection workflow setting is configured to "Do not automatically switch mailboxes", then the last PST file will not be flagged by the mail source agent and "Last PST flag found" will not be written to the Mail Target Agent log.
There are two ways in which the collection may be modified for "Last PST flag found" to be written to the mail target agent log.
1. Modifying the workflow settings in the mailbox collection Properties | Workflow to switch mailboxes, and committing the changes will enable the Last PST flag to be set by the mail source agent.
2. Move the mailboxes from a collection with the workflow settings not set to switch, to a mailbox collection with workflow settings configured to switch and commit changes.
For additional information on Mailbox switching, review the Tips & Tricks documentation noted below:
Migration Manager for Exchange 8.7 Tips & Tricks http://usdownloads.quest.com.edgesuite.net/Repository/support.quest.com/Migration%20Manager%20for%20Exchange/8.7/Documentation/MigrationManager_8.7_TipsAndTricks.pdf#search=tips & tricks
Migration Manager for Exchange 8.6.1 Tips & Tricks http://usdownloads.quest.com.edgesuite.net/Repository/support.quest.com/Migration%20Manager%20for%20Exchange/8.6.1/Documentation/MigrationManager_8.6_TipsAndTricks.pdf#search=tips & tricks
Migration Manager for Exchange 8.6 Tips & Tricks