Http POST suddenly returns status 7 when sending data to a server

Suddenly, since May-10 13:32 my http POST to my home page server at returns status code 7, meaning the imp server can not connect. So data does not arrive there and the guys at says everything is OK at their side. The say they need connection diagnosis or logs from the imp side. Can you supply this. The application is up and running, and repeatedly trying to send to /

The server has blocked the imp server. I verified this manually - so the issue is at their end. More detail is in my email reply to you.