every email should get a response, even if it isn't an answer.
Unanswered emails leave the sender to create their own answers,
which isn't good. If nothing else, the administrator should respond
with, "I will add your concern to my very lengthy to-do list and
look into it in due time. Do not expect a speedy reply." At least
then the person will know it was received and not to expect anything
Posts on this thread, including this one