1. Right-click Advanced ► Junk Fax filter node, and select 'Properties'. This will bring up the junk fax filter dialog.
Delete faxes received from fax machines with an empty CSID: If you wish to be very stringent you can refuse all faxes with empty CSID's. Note that there is a big chance that valid faxes will be marked as junk faxes.
Keep a copy of junk faxes: This option will store all junk faxes in a folder, so that you can review the junk faxes before deleting them.