" You have impressed us S17" emails...are these routine or have any meaning?

I think the schools definitely know test score ranges. One of the first e-mails my son got after his last ACT test said

Congratulations, NAME!!!

We heard you did pretty well on a certain college-related standardized test, which means—if it hasn’t happened already—your inbox and mailbox will soon be overflowing with college brochures, leaflets, pamphlets, postcards, and emails—lots and lots of emails.

blah blah blah

P.S. Also, don’t worry! Colleges don’t know your actual score. We just know you ranked in a top percentile.