We know. You’re so busy. 800 people applied to the job you posted and you just can’t imagine how to communicate with that many people at once.
Oh, yeah, right. It’s 2015.
Mail merge was created in 1980. It shipped with WordStar. You might even be able to argue it was a killer app for the personal computer because it was such a popular application. Stop being a jerk and notify people when you have filled the position. Particularly when the job you are hiring for requires post-graduate education. Seriously. Can you imagine how irksome it is to know that despite completing a decade of tertiary education and reaching the pinnacle of academic achievement that the HR manager can’t even be bothered to let people know that they should pursue other employment avenues?