I would say this problem is quite different than Two Generals, because client doesn't need to know that acknowledgment has been received, i.e., a solution doesn

I would say this problem is quite different than Two Generals, because client doesn't need to know that acknowledgment has been received, i.e., a solution doesn't require the receipt of message to be common knowledge. It it sufficient that server stops trying to send the message once it has received the ACK.