Hi, I have been trying to compare my classes with the sample xop examples in jbossws package and finally I was able to find the problem. Here are my classes: class AttachmentType { @XmlMimeType("application/octet-stream") protected DataHandler dh; .... class AttachmentTypeHolder { protected List attachments; .... In my endpoint class if I have the following method signature, then the xop works: public AttachmentType echoDataHandler(DHRequest request) but if I change the method signature to this: public AttachmentHolder echoDataHandler(DHRequest request) then the response is returned inline and not xop encoded. Is there anything I have to do to fix this. I am using Doc/Literal Wrapped wsdl, with a WSDL-first approach. Any help would really be appreciated. Thanks, View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4169948#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...