It is impossible to fork the receipt of a fax because it's a 2-way communication. You can however have a machine running an app that checks an IMAP mailbox and prints all new messages to a local printer, better yet, look into using a printer that supports Google Print, you can have the e-mail from the 3CX fax go to a distribution list that includes normal mailboxes and use the app to automatically print to the printer. We have Epson NX430 connected via WiFi all over the offices to do just that.