The ServerProxy class basically is the entry point for the SOAP adapter's
receiver. The adapter does know the message box, since it uses the Adapter
Framework's API to interact with biztalk's messaging engine.
That said, the answer to the question in your subject is no, you have to
deploy it on a bts server. If you need it somewhere else, you'll need to
create your own ASP.NET webservice that forwards the calls to the real
BizTalk server (either by calling a webservice, or by using any other