I've received thousands of emails over the past few months, and have responded to every single one (except to those few people who email me a lot...I just respond to you every now and then to let you know I'm listening), even if it was just with a simple, "Thank you."
If you sent me an email and did not received a response from me, it's because of one of the following reasons:
1) Your email got lost in space and I never received it.
2) My response to you got lost in space and you never received it.
3) My response to you got sent to your "junk" folder (I check my junk folder a few times every day and always find an email or two that shouldn't be there).
So, if you sent me an email, especially recently, and you never received a reply, check your junk folder and/or send it again.