I am wondering if there is a way to immediately bounce an email when the sender types the domain wrong, there isn’t even a MX record, and consequently no possible chance of success. I need the queuelifetime parameter to allow for downed receiving SMTP servers, but understandably customers are bothered when they mistype a recipient address and don’t find out about it for days. Is there a provision for this situation?
Not really - It’s kind of the way e-mail is supposed to work, as a maximum-effort solution. Making absolutely sure that there’s no way a message gets missed if it can possibly be delivered.