Problem with collision

I try to make a player who can collide with a wall. It sounds very simple but I encounter a problem. My player is a box - it has got a rigidbody, box collider and a simple script for moving:

using UnityEngine;

using System.Collections;

public class PlayerController : MonoBehaviour {

 public float forwardVel = 12;
 public float rotateVel = 120;

 public Quaternion targetRotation;
 Rigidbody rBody;
 float forwardInput, turnInput;

 public Quaternion TargetRotation {
     get {
         return targetRotation;
     }
 }

 void Start() {
     targetRotation = transform.rotation;
     rBody = (GetComponent<Rigidbody>());
     forwardInput = turnInput = 0;
 }

 void GetInput() {
     forwardInput = Input.GetAxis("Vertical");
     turnInput = Input.GetAxis("Horizontal");
 }


 void Update() {
     GetInput();
     Turn();
 }
 

 void FixedUpdate() {
     Run();
 }

 void Run() {
     rBody.velocity = transform.forward * forwardInput * forwardVel;
 }

 void Turn() {
     targetRotation *= Quaternion.AngleAxis(rotateVel * turnInput * Time.deltaTime, Vector3.up);
     transform.rotation = targetRotation;
 }

}

My walls have also got a rigidoby and a mesh collider but my player can't collide with them and I don't know why. I'd be very grateful, if anyone could help me. Here are two screenshots where you can see my player's and walls' components: http://i.imgur.com/QQjBCMF.jpg http://i.imgur.com/GHTsWFi.jpg