Since this is a quick howto, you will have to look to other sources if you need help setting up procmail or postfix. Don't worry about the proper permissions yet. We'll do it at the end. This will create a file that will hold your procmail recipes. Space characters do not need to be escaped.
Some people suggest using unique strings such as an email address.
Change this to reflect whatever you actually name your auto-reply text file. You will need one per info-request keyword. Just make sure it always goes above the error handling section. The error handling section isn't strictly necessary, but it's good practice. Of course, you should say something in your auto-reply.