You can find the menu on the printer's control panel below: Settings > General Settings > Fax Settings > Receive Settings > Save/Forward Settings > Conditional Save/Forward.
On the Web Config screen, you can find the menu below.
Fax tab > Save/Forward Settings > Conditional Save/Forward
You can set saving and/or forwarding destinations to the Inbox, confidential boxes, an external memory device, email addresses, shared folders, and another fax machine.
To switch between enabling or disabling the conditions, tap anywhere on the set item except for 
.
Select conditions and then make settings.
When the line port matches, the received fax is saved and forwarded.
You can also select the following conditions (the same as for standard faxing). See "Related Information" below for more details.
Sender Fax Number match
Subaddress(SUB) perfect match
Password(SID) perfect match
Receiving Time