You don't need a fax machine or phone line to send a fax. The best online fax services allow you to send and receive faxes via your email address, a mobile app, or a web portal—and sometimes for free.

Just a couple of decades ago, you needed access to a dedicated fax machine or an expensive, clunky all-in-one device to send and receive faxes. But the times are fast changing. The first internet fax ...