Joe had an older Mac that would allow him to send a fax through OS X, but his new computer won't do that in Mountain Lion. Leo says that was abandoned in the new version of OS X, so he can't do that function anymore with that old fax/modem. Joe needs a voice modem for faxing that's compatible with Mountain Lion. It'll likely need to be external. Leo prefers to use an online fax service, like eFax or MyFax. The cost is around $10 a month, and he'll be able to receive faxes as well, which are sent to his email address.