this is my situation: I have a thermostat in my bathroom which is controlled by Alexa. Now I want to automate my ventilation. For this I want to use a ESP8266 NodeMCU with a humidity sensor and a servo. However, the servo should only open the ventilation when the thermostat is off, despite a possible high humidity.
The thing is that I would like to put my ESP into deep sleep between the sensor readings (for about 120s) so I can power it with a battery. I know that I could use IFTTT and subscribe to a topic that tells me when the thermostat is switching between on/off. I guess that this will not work when my ESP is not awake all the time. So I would like to turn this around and read the thermostat state when the ESP is awake.
I would be happy about a suggestion on how to do this (without an extern webserver).
EDIT: I had a look at the tools kalyanswaroop suggested and the most convenient looking option (reading emails) seems to be not possible with ESP8266 (at least not easy). The other tools seem to be too hefty for me (or the job). I probably won't use deep sleep and use IFTTT instead. I hoped there would be an easier way.