Canon Color imageCLASS MF9280Cdn - Manual (Page 339)

Fax
5-118
Rejecting Incoming Faxes from the Unidentified Senders
7
Use [ ▼], [▲] or (Scroll Wheel) to select
<Off> or <On>, then press [OK].
<Off>: Does not reject to receive faxes from
unknown senders.
<On>: Rejects to receive faxes from unknown
senders.
8
Press (Main Menu) to return to the
Main Menu screen.
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