Another take on the same problem is to send an automatic reply saying
Your email has been received.
There are %N emails in my Inbox before yours.
Your email is important to me.
The estimated wait time for the response is %M days.
Thank you for your patience.
Seriously though, there's maybe a dozen ultra-important people in the world for whom I could tolerate a reply like that. But anyone that important really should have their secretary sorting through their email anyway.
A reply like that from someone of lower (or even equal) status would be incredibly rude.
The problem with this approach is that I would not want to auto-reply to every message, particularly not group lists or important people who expect their stuff to be read on time. I think smokesignal is a lot more subtle.
