Rule "<name>" failed to migrate because: A validation error occurred while executing the rule operation.
Answer:
This error occurs when MigrationWiz attempts to migrate a rule that is not supported in the Destination environment. Because the rule validation is different, the rule cannot be created, and will be skipped.
Resolution:
1. Manually add the rule in the Destination. It should not work, and Outlook or OWA will explain why, and what needs to be changed.
2. With that information, the customer can make the changes in the Source and remigrate, or manually create the rest of the failing rules.