Most schools take about 4-6 weeks generally to review your application and get back to you. Of course, the earlier you apply, the chances of you hearing back from them are sooner. It also depends if the schools you are applying to are on a rolling basis. If the school is on a rolling basis they will review it once your application is complete. But, if it is not, they generally wait til the deadline has passed..as far as I am aware of. I'm not sure about whether they send rejection letters or acceptance letters first...it all depends on the schools that you are applying to. Same goes with mail and electronic form---some schools will state that they will send their decision via email or mail (example: boston college). So what it really comes down to is which schools youre applying to because every school has their own way of dealing with the application process. Best of luck!