How do I block unwanted junk faxes on the HP LaserJet Pro M1530 MFP?

Press the Fax Menu button on the control panel, navigate to Receive Options, and select Block Junk Faxes. From there you can Add Number, Delete Number, Delete All, or view the Junk Fax List. The blocked fax list can contain up to 30 numbers, and when the product receives a call from a blocked number, it deletes the incoming fax and logs the activity.