Public Folder Mailbox Support for Exchange Online Protection

When adding the Exchange online node, you can see mailbox Type column in Add Nodes to a Plan window. Public folder mailbox appears in this window and in the column appears as public folder. To protect public folder, add the corresponding public mailbox into Protected Mailboxes, and then save the plan.

Note: For more information about Exchange Online public folder mailbox and permission, refer to link 1 and link 2.