hq-server.conf is from the old JON 1.x stuff and does not exist in Jopr 2.x. You must be looking at the old docs.
The Jopr docs are here:
For the SMTP stuff, see:
You set these in the installer or you can edit rhq-server.properties directly after you install.
Thanks man! I didn't knew this file was changed...
So I just altered some settings on the file: