Default [Q] Use Cellular connection when Wifi cannot connect to host


I have swapped over my Windows Phone device for a new Android device, and i am having a small problem.
I am always in range of a WiFi connection during the day that only has Port 80 open, which i use for a lot of my work, but with only port 80 being open i cannot pickup my emails. With my Windows Phone the WiFi would go out looking for a connection and when it failed it would use the Cellular connection and pick up my emails. But i have found with Android with WiFi turned on it closes the Cellular connection meaning i cannot pick up emails while i am working.

I have searched the web for an answer but i have yet to find one. Does anyone here know of a way of enabling this?