How to send the score by Email?

Hello there
I want the player to send me his score in the game -by Email - by clicking a button.
I know the way of Whatsapp, But it let the player do that or not, but by Email, I will make him click a button to finish the game, And at the same time to send that Email.
I miss the code for that, Any help!?

Hi everyone
I still need this option, Any advice?

And I want the student to play the game for two times only not more, How is this?