Configuring MTOM
Binary content often has to be re-encoded to be sent as text data with SOAP messages. MTOM enables you to selectively encode portions of the message, making it possible to send base64-encoded data as well as externally attached binary data. You can configure MTOM message encoding at the global level in the axis2.xml file or at the service or operation level in the services.xml file. Set the enableMTOM parameter to the one of these values:
true - response is always MTOM-ized in case the message includes binary data of schema type xmime:base64Binary.
false (default) - response is always non-MTOM-ized, even if the request is MTOM-ized.
optional - response is MTOM-ized only if the request is MTOM-ized.