Below are the supported backup source for Microsoft 365 Backup and Restore.
Mailbox Level: Outlook, OneDrive, Personal Site and Public Folders
Folder Level for Outlook Mailbox: Inbox, Drafts, Sent Items, Deleted Items, Archive, Calendar, Clutter, Contacts, Junk Email, Notes, RSS Feeds, Tasks and Trash
OneDrive Items: Folders, Files and Access Permissions
Public Folders Level: Folders and Files