proxy1.xml

<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="testProxy"
       transports="https,http"
       statistics="disable"
       trace="disable"
       startOnLoad="true">
   <target>
      <inSequence>
         <log level="full"/>
         <log>
            <property xmlns:m0="http://ws.apache.org/commons/ns/payload"
                      name="payload"
                      expression="$body/m0:text"/>
         </log>
         <property xmlns:m0="http://ws.apache.org/commons/ns/payload"
                   name="payload"
                   expression="$body/m0:text"/>
         <script language="js">var payload= mc.getProperty('payload').trim();var newPayload= payload.replace("send by","from");mc.setProperty("newPayload",newPayload);</script>
         <enrich>
            <source type="property" clone="true" property="newPayload"/>
            <target type="body"/>
         </enrich>
         <log level="full"/>
      </inSequence>
      <outSequence>
         <send/>
      </outSequence>
      <endpoint>
         <address uri="http://localhost/testEP"/>
      </endpoint>
   </target>
   <description/>
</proxy>