Where to send NSD files?

Hi,

I have a domino server, which sometimes suddenly are going down.

The domino Windows at the server is simply gone, and no error message appear, while windows is running fine.

I can afterwards start the domino server again … and it can work for months … before it suddenly again is closing the domino windows without any error message.

I have at other forums be told, that I have to send NSD file to Notes support, where they can see the reason … does anyone know where I can send it … or even better … anyone know how to solve this problem