Endless falling

Hello.

First of all, I’m sorry for all mistakes you will see in ths text, English is not my native language.
Well, Unity is new to me but i’m starting to learn it. I want to go little by little, so first of all, I made a box in 3ds max and imported it in Unity. I made a terrain (Is Trigger is not checked). When I apply rigidbody to a box I made in Unity, it falls down and it bounces off as it should. The box I made in 3ds max (after applying rigidbody) just goes trough the terrain and it doesnt stop falling. What is my problem? Can you please help me?

You need to add a collider (Component->Physics->some kind of Collider)

Thank you very much. It works now.