Exchange mail box restore is failing with error code 5 in NBU6.5.4

You cannot restore a mailbox to a normal filesystem folder. You can only restore to an Exchange mailbox.

See the following sections in the Exchange for NBU manual:


■ The destination mailbox must exist to successfully restore a mailbox.
■ When a mailbox is restored, all folders and messages that are contained in the mailbox are restored. You can choose to restore specific folders or messages or both from the mailbox backup image.
■ When a folder is restored, all subfolders and messages that are contained in the folder are restored. You also can choose to restore specific subfolders or specific messages or both from the folder backup image.


Redirecting a restore of mailbox objects or public folders to a different path

Requirements
The following are requirements for redirecting a restore.
■ The NetBackup directive Microsoft Exchange Mailboxes:\ or Microsoft Exchange Public Folders:\ of the destination path cannot be changed. If it is changed, NetBackup does not recognize that it is an Exchange mailbox or public folder restore. NetBackup then attempts to restore the objects as normal files.
■ If the destination path’s mailbox name is changed from the original, the destination mailbox or destination folder must already exist. It also must have an associated user account.
....
■ When redirecting mailbox backups, if the third segment of the destination path is modified (the Exchange folders “Top of Information Store,” “Views,” “Finder”), the selected object is restored to that specified folder name. The new folder can be seen when you browse for backups and is backed up on subsequent backups of that mailbox. However, the folder and any subfolders and messages in that folder cannot be viewed by using Outlook.