A few years ago, a medical school applicant told me the following story:

This pre-med decided to write follow up notes to all the schools at which he had interviewed, usually a good idea. However, he was upset to receive a brusque note from one of the institutions telling him that a) he should have read their policies; they do not allow post-interview contact and b) he was rejected from the school.

I found the school’s note pretty severe, and I strongly suspect the post-interview contact was not related to his rejection. (As an aside, he successfully and happily matriculated at another school.) But this story is a reminder that it’s important to read institutions’ policies about post-interview contact. Most places welcome written updates, but it’s essential to confirm before you send.