True, SOAP supports more protocols than HTTP. However, it does not do so by magic. Ther are bindings for each protocol. And if one can write a SOAP binding for MIME, then one can just as easily write a Simple XML Payload Protocol (my ugly coinage) binding for MIME. In fact, any protocol that SOAP suppports could be supported with a simple protocol using pretty much the same mechanisms as SOAP, except with the elimination of the SOAP:Envelope, and the separation of the SOAP:Header elements into direct extensions of the host protocol.

I realy see no concrete reason why this can't b as flexible as SOAP, and from the XML processing POV, there re numerous reasons why it would be more flexible.

--Uche