How do I send a fax using firefox or gmail? I have printed a set of instructions which start out with the use of a verification tool to determine whether the number I want to send a fax to is within the "fax service area". I don't understand this statement. I can use my fax machine to dial the number, most any number world wide, and send a fax to the number. Why would I want to use Firefox or Gmail to send a fax when I already have a fax machine? Sometimes my fax machine is busy for longer than I can wait.