Mail it to the admission office in C/O your RC.
As for a letter of recommendation from someone "important", it doesn't hurt.
But some of us that are involved in the admissions activities, we don't see any value in LORs unless the recommender has right qualifications and knows the candidate.
So a LOR from someone that never served in the military to say the recommendee will be a great military officer is less creditable
Or a LOR stating I served with the recommendee's parent, so the recommendee will be a great military officer is not so creditable.