You can use [Scripting Layer for Android (SL4A)](https://code.google.com/p/android-scripting/) + [Tasker](https://play.google.com/store/apps/details?id=net.dinglisch.android.taskerm&hl=en) (3 USD), and follow [these instructions](http://tasker.wikidot.com/automatic-email-low-battery).

![enter image description here][1]


  [1]: https://i.sstatic.net/iLdgl.png