That is a strange thing to be coming from the mouth of a four year old. Those who are so young shouldn't have email accounts, even in this day and age. Still, Tony does say this, and I have an explanation for why.
I let Tony play on my laptop. I have showed him the Microsoft Train Simulator program and he loves it. He can spend hours on end playing with the trains. It is nice that he likes the trains but unfortunately, his liking the program means I can't use my laptop myself. Tony doesn't let me use the laptop even for a short time. I ask him if I can check my email and he says no!
So, you see, Tony has picked up the expression from me. He doesn't know its exact meaning, but he has gathered that the expression is a request to yield the laptop.