I've used FAXstf for years with good success. It was never a great program but it was better than Apple's weak Fax capabilities and what little other competition there was. It was always a little persnickety but I could always get it to work. Fortunately I never had to call or ask for support. I finally did the upgrade to OSX10.5.5 (all the way from 10.4.9) and one of the few broken apps was FAXstf 10.8. I had to purchase the upgrade to 10.9 for supposed OSX10.5.5 compatibility. I depend on faxes for my business and spent pretty much a full day trying to get it to work properly with no success. This application puts files everywhere. Half of them invisible. Almost impossible to remove or find everything it installs (in true Windows fashion). Tech support barely read my emails (replied with canned responses for morons) and I can't afford three or four days of email back-and-forth while I beta test their product. This is a buggy and barely functional application that I would say is barely supported by Smith Micro (hell, you have to TRY to find it on their website). Make sure, if you're determined to own it, to download their fixes and utilities (FaxPrint Installer and Fax Magic) that are required to allow you to spend at least a few hours of entertaining troubleshooting. Bummer.

So, I finally gave up and started looking for an alternative. Last time I had checked there was nothing comparable. This time I found PageSender and it saved my butt. Installed in a snap with minimal intrusion. It just works, like a good Mac app should. I was even able to salvage, with some work, my cover pages. I was up and running in a fraction of the time it took me to unsuccessfully troubleshoot FAXstf.
All I can say is good riddance to SmithMicro and I'm headed right over to PageSender to give them 4 stars. Also, PageSender is $10 cheaper!