Boundedness of an Operator in an Orlicz spaces

Question

Let $(X,\Sigma,\mu)$ be a finite-dimensional space and let $T:L^{\Phi}\to L^{\Psi}$ be an integral operator from one Orlicz space t another defined by $(Tf)(x)=\int_{X}K(x,y)f(y)d\mu.$ I am trying to show that the operator $T$ is bounded that is we have to show that $||Tf||_{\Psi}\leq C||f||_{\Phi}$. I have proved that $||Tf||_{\Psi}\leq M$ for some $M>0$. Now is there any way to so the final result that $T$ is the bounded operator? I just need some hint not solution, thanks.