Webservice response as HTML instead of SOAP message - web-services

Question

I am working on a wso2 scenario in which I send a SOAP message to a webservice and then receive and manipulate the answer. For this purpose I have TWO Webservices. One is placed in a test environment (1) and the another is the live one (2).
I have no access to the webservice code, I'm just a user.
The problem is:
Via SOAPUI
I'm able to use the service from Webservices (1) and (2). No error, everything works fine.
Via WSO2
I'm able to use the service from webservice (1) but when I point to the webservice (2) I get a HTML 403 Forbidden response instead of a SOAP/XML message.
Am I missing something or this could be a misconfiguration of the webservice?
Following my in/out requests:
Sequence:
<?xml version="1.0" encoding="UTF-8"?>
<sequence name="pricing" trace="enable" xmlns="http://ws.apache.org/ns/synapse">
<smooks config-key="smooks-csv.xml">
<input type="text"/>
<output type="xml"/>
</smooks>
<iterate expression="//product" id="iterateXML" sequential="true"
xmlns:ns="http://org.apache.synapse/xsd" xmlns:ns3="http://org.apache.synapse/xsd">
<target>
<sequence>
<payloadFactory media-type="xml">
<format>
<xyz xmlns="http://tempuri.org/">
<safeKey>$6</safeKey>
<storeId>$5</storeId>
<articleId>$1</articleId>
<barcode/>
<sku>$2</sku>
<price>$3</price>
<discount>$4</discount>
</xyz>
</format>
<args>
<arg evaluator="xml" expression="//articleId"/>
<arg evaluator="xml" expression="//sku"/>
<arg evaluator="xml" expression="//price"/>
<arg evaluator="xml" expression="//discount"/>
<arg evaluator="xml" expression="//storeId"/>
<arg evaluator="xml" expression="//key"/>
</args>
</payloadFactory>
<in>
<header name="Action" scope="default" value="http://tempuri.org/xyz"/>
<send>
<endpoint>
<recipientlist>
<endpoint key="PS_PRICING"/>
<endpoint key="fileSave"/>
</recipientlist>
</endpoint>
</send>
<drop/>
</in>
<out>
<send/>
</out>
<log level="full" separator=";">
<property expression="*" name="ResponsePriceUpdate"/>
</log>
</sequence>
</target>
</iterate>
</sequence>
UPDATE:
After testing using TCPMon and TCPTrace I got the following:
Via SOAPUi
If I send the message SOAPUi -> Live Webservice - Works fine! (Picture a)
If I send the message SOAPUi -> TCPMon/TCPTrace -> Live Webservice - 403 Forbidden! (Picture b)
It doesn't make sense at all to me. I'm running out of ideas.
(a)
(b)

Answer 1

For the people who has found this question relevant:
The problem was in the server-side. Server was rejecting some "unknown" sources of incoming traffic.

Answer 2

Maybe add ?wsdl as postfix to the url: http://sample.com/webservice.asmx?wsdl