…considering an automated reply takes virtually no effort.
Except that is not entirely true.
Oh, yes, a truly automated acknowledgement system takes negligible effort to run; a computer detects the incoming message and sends a meaningless reply within seconds. But what does it cost to put such a system in place? If a dedicated platform is being built to handle submissions – and in the real business world, a platform like this has a mid-to-upper six figure price tag – then it's a safe bet. But for anything else, it's either an ugly hack that doesn't work properly or…
If you are talking about doing it manually, how long is that "virtually no effort"? It still takes someone to open the email, determine that it is a submission, copy-paste a generic reply, and send it. In another thread, we saw a figure of 150 submissions per week, per agent. That's 30 per day. How long does the check, copy-paste, send process take? Less than a minute, yes. Mabye all of 15 seconds? But that's still over half an hour per week.
At wehich point, I refer you to that automated email. The one that is utterly meaningless. All it told you was that the system processed it. But in the digital world, while there is a negligible chance that any single submission may not be cleanly processed, the act of sending by email / submission form offers as much confirmation of reciept as that automated / time-wasting generic reply.
Also, such a reply could only tell you that it's in the queue, not that it's been looked at.