When sending out data through HttpService, you might face to problem, that the receiving side is not able to correctly decode characters from the payload. This might be caused by the lack of the encoding info. HttpService by default encodes the outgoing content in UTF-8, but it doesn’t attach any encoding info to the request. In such case, the encoding, which is automatically assigned to the request, depends on the system settings. To prevent this problem, you can set the encoding in the ContentType parameter of the HttpService. Instead of usual text/xml you need to use text/xml; charset=utf-8.