Send Using config invalid

[ita-yishunss]

CDO.Message.1 (0x80040220)
The "SendUsing" configuration value is invalid.

<%
option explicit

dim strName
dim strEmail
dim strSubject
dim strMessage

strName = request.form("txtName")
strEmail = request.form("txtEmail")
strSubject = request.form("txtSubject")
strMessage = request.form("txtMessage")

Dim ObjMail
Set ObjMail=Server.CreateObject("CDO.Message")

ObjMail.To = "[e-mail]"
ObjMail.From = strEmail
ObjMail.Subject = strSubject
ObjMail.TextBody = strMessage
ObjMail.Send

set ObjMail = nothing

%>

this is the script that was use. can anyone check anything wrong with the script. I was hosting under ISS 5.1.