If there is a proxy server between your code and the internet you may need to specify the proxy details.
Dim oSOAP ' The SOAP Toolkit object
Set oSOAP = Server.CreateObject("MSSOAP.SoapClient30")
oSOAP.ClientProperty("ServerHTTPRequest") = True
oSOAP.ConnectorProperty("ProxyServer") = "proxyserver:8080"
oSOAP.ConnectorProperty("ProxyUser") = "username"
oSOAP.ConnectorProperty("ProxyPassword") = "password"
oSOAP.mssoapinit("https://www.textapp.net/webservice/service.asmx?wsdl")
Once you have an initialized SoapClient object, you are free to call methods. For example, to call the sendSMS method:
result = oSOAP.SendSMS(false, "myExternalLogin", "myPassword", "clientBillingReference", _
"clientMessageReference", "+447923456789", "+447923456789", _
"hello world", 72, 2, 4, "", "");
Response.Write(result)