I think I missed the object of the OP's post. I originally thought it was about sharing recipes, it's not. It's about not responding to or ignoring emails.
I agree with both the OP and jimithing. The OP has a right to be hurt if her friend is ignoring the emails.
There is no way to know if the email is being ignored without asking if it was received.
I would email something like:
"Hey, did you get my previous email? If not, I was asking for your fantabulous cupcake recipe. I understand if you don't want to share your signature dish, but my mouth is watering just thinking about your cupcakes. I have never had any so fluffy, light and well, without compare the best ever.
Did your DH get the raise he was hoping for? I hope your DD loved the dollhouse "Santa" was bringing......."
This would give the friend a chance to say she didn't receive the email (even if it were a fib) and to either say "thanks for the compliment, all I do is use sweetened condensed milk instead of sugar and milk in the Martha Big Cook recipe book" or "thanks for the compliment, I don't share that recipe. DH hasn't received the raise yet, but we're hoping any time now....."