There are two backup scenarios for the Recoverable Items Folder.
Before Onboarding to Dropsuite:
When the customer already has some data under the Recoverable Items Folder before onboarding to Dropsuite, we can’t back up those email messages. This is because no Microsoft API is available to process the backup of the folder during the initial backup.
After Onboarding to Dropsuite:
Once the tenant is onboarded to Dropsuite, we start the initial backup, where all email messages are backed up. Later, if the customer moves any email messages to the Recoverable Items Folder, we don’t need to back up those messages specifically as they are already in the backup.