Q:

Trying to retrieve Send Classifications through the Marketing Cloud SOAP API

I've been trying to retrieve the send classifications associated with a business unit through the SOAP API using a SOAP envelope I found here:
Get Send Classifications using FuelSDK-PHP
*request:
<Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<Header>
    <fueloauth xmlns="https://exacttarget.com">[I Insert an OAuth Access Token Here]</fueloauth>
</Header>
<Body>
    <RetrieveRequestMsg xmlns="http://exacttarget.com/wsdl/partnerAPI">
        <RetrieveRequest>
            <ObjectType>SendClassification</ObjectType>
            <Properties>ObjectID</Properties>
            <Properties>Client.ID</Properties>
            <Properties>CustomerKey</Properties>
            <Properties>Name</Properties>
        </RetrieveRequest>
    </RetrieveRequestMsg>
</Body>

The request seems to go through, but I don't get any info about the send classifications back
*response:
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
<soap:Header>
    <wsa:Action>RetrieveResponse</wsa:Action>
    <wsa:MessageID>urn:uuid:91dd2863-f8bf-4da6-a0bb-bfe762b6524e</wsa:MessageID>
    <wsa:RelatesTo>urn:uuid:6eff6d00-820b-4255-844e-727e41e91fb8</wsa:RelatesTo>
    <wsa:To>http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous</wsa:To>
    <wsse:Security>
        <wsu:Timestamp wsu:Id="Timestamp-7cfc1c1b-2c03-46dd-9184-92772bc72647">
            <wsu:Created>2016-08-31T21:34:28Z</wsu:Created>
            <wsu:Expires>2016-08-31T21:39:28Z</wsu:Expires>
        </wsu:Timestamp>
    </wsse:Security>
</soap:Header>
<soap:Body>
    <RetrieveResponseMsg xmlns="http://exacttarget.com/wsdl/partnerAPI">
        <OverallStatus>OK</OverallStatus>
        <RequestID>9e8221cb-31ac-42e9-a0ca-327e65a44077</RequestID>
    </RetrieveResponseMsg>
</soap:Body>

Is there any way for me to retrieve available send classification IDs?

A:

What endpoint are you posting to? 
This endpoint worked for me.
https://webservice.exacttarget.com/Service.asmx

