We are working to put our own code alongside the emonpi that will retrieve monitored data (voltage and total power) from the emonpi. We have added init scripts to run this code when emonpi boots. After the first reboot, we notice our init scripts remain in place, but they do not run. We did run rpi-rw to install those scripts, followed by rpi-ro.
NodeRed is the tool built into the emonpi to post data to other services. Browse to port 1880 on your emonpi to see example subscribing to the mqtt topic and sending an email alert. See nodeRed user guide page for login credentials: