A fax interface unit provides a novel way of sending and receiving a fax over a global computer network such as the internet. The fax interface unit is coupled to a legacy fax machine on one side and to both a local area network and the telephone network on the other side. When a first location transmits a fax document to a second location having an email address capable of receiving the fax document, the telephone network is bypassed and the transmitted fax document arrives as email at the second location, thereby reducing telephone cost and providing the second location with an archived document.