Embarrassed about having procrastinated, he doesn't return your voice mail and e-mail. He sits on the other side of the room in meetings and leaves before you can collar him. Your top priority is making sure you aren't him. There are lots of reasons people fail to return messages. Decision avoidance is one.
Time management is a second.
Take a quick look at your e-mail inbox. Don't sort them. Don't prioritize them. Reserve a half-hour of your time, and blast through everything that's piled up waiting for your attention. Use your best judgment and tell me what you decided.