Smoothing lines on my MoI mesh

 From:  Pozero
I am using MoI for a while and he's a HELL of a software :-) I just love everything about MoI, but now I have question about my 3D surfaces.
Here I posted a pic of my 3D mesh render. You can clearly see lines which I want to remove from my 3D surface made in MoI.
How to make that lines on my mesh SMOOTH ? These are usually some places where my surfaces are joined (where they are connected) to each other so I have lines which make my mesh looks rough? How to solve this? Which software to use ?