Brooktrout SR140 and Rightfax Logging are seperate.
For SR-140, you have to go into the Brooktrout Config Tool and go to the BTCall Parameters section - and enable API Debuging, and choose where you want the logs to be stored.
RightFax logs via the DocTransport service to the windows application logs, to enable this - go to DocTransport ->Configure Service -> Global DocTransport Settings -> change from TERSE to VERBOSE.
Save the settings and restart the services - and it's logging in more detail now.