Thank you for enquiring about our fax software!
You cannot send/receive faxes via a cable modem or DSL, or any Internet
connection. Fax machines are telephone line based. You need to transmit
data through a dial-out phone line to fax. Cable modems and DSL modems can
not connect to the phone line to dial a number or answer a call, and
there-for, cannot communicate with fax machines. You need to use a regular
data/fax modem for faxing via a computer. This is true with any fax software.