Architecture for capturing result of webservice and send result to other webservices

I am developing an application in C#. I am calling a webservice (lets call this WS1) and I want the result to be send to 1 or more other (external) webservices (eg WS2 and WS3).

In case one of the receiving webservices (for example WS2) is down, I want to make sure this call is not lost and is tried again at a later time.

What is a good architecure to achieve this? Does anyone have a link to an online document where an architecture like this is described?