It's not that difficult to respond to an email. Even if you are just an aspiring walk on, you still need to hold out for a coach who also manages to be a decent human being.
I coached a runner who was a state champ in HS but rejected by her first choice college coach because he thought her hips were too wide. This coach considered wide hips a sign of a lack of potential.(I saw her win her HS state meet and thought I had just watched one of the toughest most determined athlete I'd ever seen.) Now the NCAA coach she did end up running for injured her several times in those next four years and she never improved. Whenever she started to regain fitness he would race her until she was injured. He told her she was not durable enough, that she'd never run any faster. The runner ended up in the Olympic trials four years later. If you are really motivated then you will find a way to reach your potential with or without an NCAA team.