Hello, Here my setup: I have a TDM410P FXO connected to a POTS line. I currently have a fax machine set up to a SPA3000 FXS port but thats not working so great. I have all kinds of connection issues when sending faxes and have tried all of the different options in the SPA with no luck. I tried using a splitter on the POTS line and having it go direct to the fax AND to the TDM but then I realized that the TDM doesn't detect a dial tone before dialing out so it just grabs the line even if its in use by the fax already. I want to avoid having to have a dedicated fax line since we don't do all that much faxing. Do you suppose adding a FXS card to my TDM410p would have better results than the FXS on the SPA3000 for faxing? Can you think of any other options I may have? Thanks!