I have 2 FX0 lines coming into a Grandstream 4104 that are answered by an autoattendant. I have 3cx free edition. I need to add 1 fax machine into the office and i cannot get another line from the PSTN provider for another 3 months. can i share 1 of the FXO lines as a secondary line and fax line? what is the best way to add an analog fax machine? Can T.38 fax work with 3cx free?