again, until the game clock hit 0:00, you are still in the game. don't rule yourself out before they do. take everything as an opportunity to score. i know it's easy said than done. but we better learn how to do it to win. keep thinking, did you ask the right question? did you ask the right person? anything else you can do? anyone else you can sak? i would probably send another followup email, saying the good words like understand how busy his schedule is, how much you appreciate his help, etc. and ask if there is anyone else you can follow up with. usually, if they have nothing to disclose to you, or not the right person to do so, they would be happy to redirect you to someone else. now you have someone to bite on, and keep your chance alive. i wont send more than 3 emails, and would wait a bit longer each time. every situation is unique, use your best judgment. at least, it's a opportunity to practice how to deal with people. you didn't gain nothing, if you have the right attitude. i mean later in your career, you have much more difficult people/situations to deal with.