The document discusses 4 approaches to securing document and email attachment assets:
1) Secure Attachment Vault - Allows capturing all inbound and outbound attachments into central secure storage.
2) End Point Backups - Ensures all data on devices/machines is backed up centrally including local mail stores.
3) Email Archival - Sets up personal archival to capture copies of all mail in central storage for disaster recovery.
4) Single Instance Storage for Attachments (SISA) - Strips attachments from large emails and stores centrally to save bandwidth and server space.