How do I notify a blocked caller that he has been blocked on my iPhone 5? I have an iPhone 5 with iOS 8 installed and have blocked a person who is harassing me via my txt messages.  

I do not have a phone number for this person as he is texting me via iMessage with his email address. This person lives in Norway and I in the US. 

I have researched and have found that when blocking a caller on an iPhone the caller will NOT be notified that he has been blocked. He will receive a "message sent" notification on his end. I do not want this caller to have the satisfaction of thinking that I have received his message. 

I also do not want him to have the satisfaction of receiving a text from me telling him that he has been blocked.

I would like for him to receive a message notifying that he has been blocked immediately after he sends me a txt.  

Is there any way to accomplish this task?
No, this is not possible. Blocking a user will still deliver the message to your account, it just won't be shown. You can't prevent a message from being sent to you, except by creating a new account.