Maximum request length exceeded?

I am using the Web Service Toolkit in Access to generate the code needed to call a Web Service which in turn sends an email using SMTP. My problem is when sending a large attachment with the email request, I get the error "Maximum request length exceeded". In ASP.NET is would set the maxRequestLength in httpRequest to change the upper limit in the caller. How do I do the same thing from VBA using the generated SOAP call?

Private Sub Class_Initialize()

'*****************************************************************

'This subroutine will be called each time the class is instantiated.

'Creates sc_ComplexTypes as new SoapClient30, and then

'initializes sc_ComplexTypes.mssoapinit2 with WSDL file found in

'http://localhost:3038/EnterpriseDataService.Host/U...

'*****************************************************************

Dim str_WSML As String

Dim c_WSDL_URL As String

'--Read in the WebService URL so that this can be migrated effectivly

c_WSDL_URL = GetAppSetting("Administrative System", "EnterpriseDataService", "UtilityServiceWebService")

If GetCurrentEnvironment() = PROD_ENV Then

c_WSDL_URL = Replace(c_WSDL_URL, "ENVIRONMENT", "")

Else

c_WSDL_URL = Replace(c_WSDL_URL, "ENVIRONMENT", "-" & GetEnvironmentName)

End If

str_WSML = "<servicemapping>"

str_WSML = str_WSML & "<service name='UtilityService'>"

str_WSML = str_WSML & "<using PROGID='MSOSOAP.GenericCustomTypeMapper30' cachable='0' ID='GCTM'/>"

str_WSML = str_WSML & "<types>"

str_WSML = str_WSML & "<type name='EmailInfo' targetNamespace='http://enterprisedataservice.datatypes/2007/09' uses='GCTM' targetClassName='struct_EmailInfo'/>"

str_WSML = str_WSML & "</types>"

str_WSML = str_WSML & "</service>"

str_WSML = str_WSML & "</servicemapping>"

Set sc_UtilityService = New SoapClient30

sc_UtilityService.MSSoapInit2 c_WSDL_URL, str_WSML, c_SERVICE, c_PORT, c_SERVICE_NAMESPACE

'Use the proxy server defined in Internet Explorer's LAN settings by

'setting ProxyServer to <CURRENT_USER>

sc_UtilityService.ConnectorProperty("ProxyServer") = "<CURRENT_USER>"

'Autodetect proxy settings if Internet Explorer is set to autodetect

'by setting EnableAutoProxy to True

sc_UtilityService.ConnectorProperty("EnableAutoProxy") = True

Set sc_UtilityService.ClientProperty("GCTMObjectFactory") = New clsof_Factory_UtilityServic

End Sub