So we would need to reply individually to every single email (i.e. hit reply and cut-paste). 50 emails would probably be 15 minutes of work, but I would rather not waste that time.
The main point is that some of the resumes we get are completely off topic. I wish I could showcase some examples, but alas that would probably get us into trouble. Why should we waste the time in responding to auto posters, people who just attach a resume with no cover letter, or misspell subject lines?
I think our new system would solve all of this, just need time to code it this summer.