Automatic send email notification for tester



Hi all.
I have issue about automatic send notification for tester.
After build successful, I upload apk file to Fabric but tester not reciever email notification " App ready to test".
So i want auto send email for tester on group test Fabric.

So how to config file circle.yml to do it. I use Android Studio 2.0 and gradle 1.20.1
Please help me.