> Especially as most businesses aren't going to have an automatic way to do this easily...
I find myself surprised by the idea that, in most cases, any business is not used some form of automated solution for resume filtering. In that case, it seems like automated rejection responses should be a capability provided by that solution. I can't recall the last time I went through an application process that wasn't clearly provided to the company I was applying for by a third-party company, though I'll grant that the companies to which I might apply are likely not those to which you are referring.
I find myself surprised by the idea that, in most cases, any business is not used some form of automated solution for resume filtering. In that case, it seems like automated rejection responses should be a capability provided by that solution. I can't recall the last time I went through an application process that wasn't clearly provided to the company I was applying for by a third-party company, though I'll grant that the companies to which I might apply are likely not those to which you are referring.