that will depend on the other user's CAD software. all of the neutral formats (step, iges, parasolid, etc.) will not tranfere features. a lot of CAD softwares can open native files directly, with varying amounts of success. see if he can open a SW file. that will be your only way to SEND features. some CAD software can take the geometry from an imported file (such as a step file) and deduce features for it (in SW this is called FeatureWorks). either way, you will be limited based on the CAD software at the other end.