1. analyze the strengths and weaknesses of each sentence, and
2. revise the message so that it follows this chapter's guidelines.
I regret to inform you that you were not selected for our summer intern program at Equifax. We had over a thousand resumes and cover letters to go through and simply could not get to them all. We have been asked to notify everyone that we have already selected students for the 25 positions based on those who applied early and were qualified.
We're sure you will be able to find a suitable position for summer work in your field and wish you the best of luck. We deeply regret any inconveniences associated with our reply.