I can relate. I always try to respond to people's requests for information, that same day if possible, and if not, I'll send a quick email saying when I can get back to them.

Part of my job is collections, and I know why customers who don't pay their bills ignore me. It's co-workers, our own sales people, customer service reps, etc. who I need information from in order to do my job of collecting money that I'm baffled by. We are, supposedly, on the same team, and working towards the same goal of making money for the company, so why do they make my job more difficult by ignoring my email requests? This is one of my pet peeves.