The Hard Disk Drive (HDD) transforms the MFP into an information hub. The HDD is required for Document Server, Locked/Hold/Stored Print, Sort/Stack, Print from USB/SD Card, Store File, Scan to Folder/Memory, Mail to Print, Preview Before Transmission, Managing received fax documents using Web Image Monitor, Delivering files received by fax and Encryption and Signature for Internet Fax/E-mail. Data Overwrite and HDD Encryption are available when the HDD is installed.