You can use Printout3D or Export to make the STL file from your graphics. I have never used Printout3D so can't say anything other than read its documentation. If you use Export, there is probably less checking on whether the object is printable, but you will be able to visualize it, as below.
ht = .5;
test = Table[{RandomReal[], RandomReal[], RandomReal[]}, {1000}];
Export["boxes.stl",
Graphics3D[Map[{ Cuboid[(#), (# + {ht, ht, ht})]} &, test]]] ;
Import["boxes.stl"]
Notice I removed the options you used, that would not print.
