Problem using CDONTS.dll error 807007e

I have a Windows 2003 Standard SP2 server running IIS version 6 with 1 custom website.
I am having trouble sending email using CDONTS.dll, below is a copy of the code from "SendEmail.inc":

Dim MyCDONTSMail

Set MyCDONTSMail = Server.CreateObject("CDONTS.NewMail")
MyCDONTSMail.From= "Website<no-reply-possible@emaildomain.com>"
MyCDONTSMail.To= Recipient
MyCDONTSMail.Cc= CCTo
MyCDONTSMail.Subject= Subject


'-------------------------------------------------- Define Header -------------------------------------------------------------------
messagetext =       Messagetext & "<font face=verdana size='-2'><b>Autogenerated message from Hemelnet</b><br>"

'-------------------------------------------------- Define Message -----------------------------------------------------------------
messagetext =       Messagetext & "<font face=verdana size='-2'> ************************************************************************************************** <br><br>"
messagetext =       Messagetext & "<br>"&Subject&"<br>"
messagetext =       Messagetext & "<br>"&Details&"<br><br>"
messagetext =       Messagetext & "<br>"&LinkMsg&"<br><br>"
'----------------------------------------------------- Define Footer -------------------------------------------------------------------
messagetext =       Messagetext & "<font face=verdana size='-2'> ************************************************************************************************** <br>"
messagetext =       Messagetext & "<br><br>Kind regards <br><br>" & ProperName & "</font>"

' -----------------------------------------------------------------------------------------------------------------------------------------

MyCDONTSMail.BodyFormat = 0
MyCDONTSMail.MailFormat = 0                   
                        
MyCDONTSMail.Body= messagetext
MyCDONTSMail.Importance= 1
MyCDONTSMail.Send
set MyCDONTSMail=nothing

'=================================================== Record that email was sent =======================================

Set mailRS = Server.CreateObject("ADODB.Recordset")
      mailRS.open "SELECT * FROM SentMail", objConn, 3, 3
      mailRS.AddNew
      mailRS("SentBy") = ProperName
      mailRS("SentFrom") = Section
      mailRS("Recipient") = Recipient
      mailRS("CCTo") = CCTo
      mailRS("Subject") = Subject
      mailRS.Update
      mailRS.Close
set mailRS = Nothing


%>
<table width="600">

</table>



The code fails on line 11, which is:
Set MyCDONTSMail = Server.CreateObject("CDONTS.NewMail")

with the error:
error '800707e'
C:\INETPUB\WWWROOT\TESTENV\ADMIN\../includes/sendemail.inc, line 11

This error suggests an issue with the registration of the CDONTS.dll file.
I have made sure that CDONTS.dll has been registered with the command:
regsvr32 C:\WINDOWS\System32\CDONTS.dll
Have un-registered and re-registered it again, also registered scrrun.dll, switched off the Anvti Virus temporarily.

Any ideas?

Thanks,
Steve