Does iPhone send Read receipts to unknown IMessage or SMS?

With the rise of spam texts from unknown numbers framed as someone asking how your day is going, etc., it would be good to have the default functionality or at least an option to not send numbers outside your contacts the “Read” receipt. Even when these messages are deleted and reported as junk, spammers have nearly unlimited additional numbers they can access to keep trying to reach a person once they’ve verified it’s active due to the “Read” status.