What version of IS are you using? What do you mean by “mimesoap”?
The soapDataToString service takes a soapData object as input. This is a WM-specific java class, that gets created by the content handler when a soap message is posted to IS before it is passed to one of the default soap processors or a custom soap processor that you have created and registered.
What is creating the “mimesoap” message? I don’t think this is supported in IS 6.1 and earlier (perhaps not 6.5 either, but I haven’t tested this) You can probably enhance your custom soap processor to do so, but it may take a bit of work.
Mark
#API-Management#webMethods#soa