Firstly I would like to thank the people who were discussing here!
I used ArtCAM 2017 and face difficulties in sending the codes to Shapeoko 2 CNC machine (the version before X-carve). Finally the post processor that worked is "Mach3_4(MM)(*.TAP)" ! I dont know whether it is the correct PP to be used but it worked.
Now I can mill 3d surfaces!