Try this:

oSession = CreateObject("MAPI.Session")
oSession.Logon("Microsoft Outlook Internet Settings",<password>)
oNewMessage=oSession.Outbox.messages.add()
oNewMessage.Subject = "This is an e-mail using CDO"
oNewMessage.Text = "Welcome to the world of CDO"
oRecipient = oNewMessage.Recipients.Add()
oRecipient.Name = "John Doe" && This name must appear in your address book.
oRecipient.Resolve && If name does not appear this will cause an error.
oNewMessage.Update()
oNewMessage.Send()
oSession.Logoff()

>Hi,
>
>Using CDO ( in windows xp ), how to authenticate in SMTP server ( to send a mail ) ?
>
>Thanks