Jon is correct: I have Updox Central running and faxes can be saved to the SEND TO UPDOX folder as Marty says. But no upload when Updox closes due to inactivity on the fax computer. So other computers using Updox don't have access to incoming faxes. I haven't tried changing the computer running Updox central to the same computer with the SEND TO UPDOX folder, so I'll try that.
I did also try to have my fax machine email the fax to my "(practice name)@myupdox.com" address. It works even if Updox is inactive. However, it adds an email cover page which can't be removed when the fax is imported into AC. I also reported this to Updox. Their response could be summarized as "so what".
I really like Updox, and would never give it up, but there still are issues.
