Z-Way alarm for Freezer

[kudden]

New stupid qustion.

I have started to try the Z-Way ang some Fibaro universal sensor to monitor my cool storage at home.
I have the sensor in the Z-way, but hove do I get it to send me a mail when wrong in freezer?
The Rules function seems not to work with negative values (-16celsius)

Some one ho use this setup ?
Or have I selected the wrong system?

[PoltoS]

What is wrong with rules? Please clarify what is not working and we can fix it