Artists send their portfolios to game development companies like bioware, crytek, or activision. Microsoft and Sony merely publish and develop consoles.
If you want to work in the industry, you need more than a portfolio of drawings and 3D models. You should have experience with making Mods and a completed project to boot.
Go to www.moddb.com and see if you can at least find one team that will take you on as a concept artist. Until then, you can try to generate all the contacts you want - but don't expect a job offer.