does not send incoming faxes to emails

I have the HP Officejet 8600 Plus   

First let me say, I am able to scan something to an email and it works fine.  BUT if I am not in the office and a fax comes I need it to send as pdf to my email and it will not do it.

  I set it up correctly, I have all the SMTP settings correct from Time Warner in Austin, TX  SMTP settings are   mail.twc.com    with port 587    After I enter all information and go to save and test, I get a big red X that says it did not setup correctly but does not say what is wrong.    I am familiar with doing this setup, because I also did my Brother MFC-8710dw at home correctly and it works fine.  Same Timewarner settings and all.   Can someone please tell me why it does not allow me to save and test the settings