An auto response is a good idea to implement, it does provide a feeling that the sender is not being ignored.
Many of the emails I receive have very similar questions. I have canned responses to many questions in a Word document and copy and paste corresponding answers to their questions, which takes care of a very large majority of emails I receive. If needed I tailor the canned response to the question.
For things that require lengthier replies I may copy and paste a several page long Word file that addresses their issue. For other items I simply have to refer them to another source.