POST data to server with GPRS


I got this project where I am supposed to send a bunch of data from my Arduino Uno with an Arduino GSM shield to a server, but I can’t seem to understand how the POST request should look like. What I have now is:

if (client.connect(server, port))
    // Make a HTTP request:
    client.println( "POST /Service HTTP/1.1" );
    client.println( "Host:" );
    client.println( "Content-Type: text/xml; charset=utf-8" );
    client.println( "SOAPAction: \"publishXmlEvent\"" );
    client.println( "Connection: Close" );
    client.println( DATA TO BE SENT );

The data to be sent will look like this:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="" xmlns:xsi="" xmlns:xsd="">
    <publishXmlEvent xmlns="">
        &lt;?xml version="1.0" encoding="utf-8"?&gt;
        &lt;Event xmlns:xsi="" xmlns:xsd="" about="f4605a3b-cad6-4198-a4d2-9760e799aa81" prefix="inertia: linksmart:" eventStatus="Production" schemaVersion="0.5.0" systemsID="LinkSmart" xmlns=""&gt;
        &lt;EventType typeof="TempSensorDevice" /&gt;
        &lt;Topic typeof="OBSERVATION" /&gt;
        &lt;IoTEntity xmlns=""&gt;
        &lt;IoTProperty about="01842FD8:TempSensorDevice" typeof="inertia:TempSensorDevice"&gt;

I’m using a Arduino Uno r3 with an Arduino GSM shield and I am using the web client example as a base for the project. I don’t know if the data to be sent is to much for the arduino to handle…