I've a Business Unit in SC+ which I want to completely delete to save space and reduce daily backup size. I tried archiving the BU, archiving the request, deleting the request. But none of these reduced the file size, deleted the email attachments or reduced the backup time or space. (Have nearly 480 Requests with attachments in the range of 1-5MB which will make a substantial difference in backup & file storage)

Pls. advise how to permanently delete requests with their file attachments or stop them from being included in backup.

Thanks.