The "SendUsing" Configuration Value is Invalid

I recently moved a VBScript script from one server to another. The new server did not have an SMTP server on it. When I ran the script (which emailed) I got a The "SendUsing" Configuration Value is Invalid error. Having already spent sometime recently using VBScript to email via Gmail, it was an easy fix for me. I specified the server and port and off it went!

Dim objMessage

Set objMessage = CreateObject("CDO.Message")
objMessage.Subject = "MY_SUBJECT"
objMessage.From = "FROM_ADDRESS_SAME_AS_USER_NAME"
objMessage.To = "TO_ADDRESS"
objMessage.TextBody = "MY_MESSAGE"

objMessage.Configuration.Fields.Item( _
"http://schemas.microsoft.com/cdo/configuration/sendusing") = 2
objMessage.Configuration.Fields.Item( _
"http://schemas.microsoft.com/cdo/configuration/smtpserver") = "IP_OR_NAME_OF_SERVER"
objMessage.Configuration.Fields.Item( _
"http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 25
objMessage.Configuration.Fields.Update

out = objMessage.Send
Set objMessage = Nothing