Adagio's Fax Driver expects an external modem connected to a serial port and communicating through "AT" codes. It does not expect to be communicating through a printer driver or to a fax server shared on the network.

You asked what we recommended, and our recommendation is that faxing is so uncommon as a communications method between companies (and non-existent between users), that it is not worth the consulting and troubleshooting time to attempt to get a fax modem working in 2015.