You wouldn't be able to use Mightyfax with DSL. You would have to get a network fax machine to connect the phone line and your computer/router. It would allow you to fax quickly from AC. You could send faxes through internet/DSL using
MetroFax,
FaxAge and many others, but you would have to pay for the faxes sent/received, and you wouldn't be able to send them directly from AC.
