I apologize, that post must have been caught in our spam folder. Unfortunately I can not find it. 

Would you mind posting it again? 

Can You try one more time to find it. Because there was a stack and now I don't have it. Problem is that when I call OAuth signed FetchExternalEmail method by JSON request I get "Internal server error" but in my post was whole request with resposne :(

Szymon,

I am unable to locate your original post.  I'm sorry.