This article applies to the Mailbox migration product
The principle of delta pass is that already migrated items are never migrated again to avoid duplicates.
Therefore, you cannot reuse the same license to migrate 2 times the same mailbox.
If you want to remigrate a second time the same mailbox, you have to delete the user from the cloudiway user list, recreate him and assign a new license.
From the platform point of view, this will be considered a new user to migrate and it will be entirely remigrated.
First, you will have to empty the target mailbox because items will be migrated a second time.
Same logic applies across all the platform and is the same for Drives, Sites, Groups, and Teams migration