Please follow the below steps to enable mail forwarding for any user.

1] Login to Admin Panel using the Admin ID.

2] Select the user from the right pane.

3] In the user's detailed information, select forwarding.

4] For only incoming forwarding select received and for incoming and outgoing forwarding select send and receive.

5] provide the forwarding id in the 'forward to' field.

6] Save the changes.