If you are having errors such as:

The "SendUsing" configuration value is invalid.

/aspFormMail.asp, line 346

Perform the following by opening up your aspFormMail.asp file and do the following (look for the items in read and replace with the items in red before "replace with":

Find:

  Case "CDOSYS"
    'Use the CDOSYS component
      
     Const cdoIIS = 1
 
    'Create CDO message object

     Set objMail = CreateObject("CDO.Message")
     With objMail
       'Load IIS configuration
       .Configuration.Load cdoIIS
   
       'Set email adress, subject And body
       .To          = strToEmail
       .From        = strFromEmail
       .Subject     = strSubject
       .TextBody    = strBody
   
       'Send the message
       .Send

     End With

     Set objMail = Nothing

Replace with:

Case "CDOSYS"
'Use the CDOSYS component
sch = "http://schemas.microsoft.com/cdo/configuration/" 'new

Set cdoConfig = Server.CreateObject("CDO.Configuration") 'new

With cdoConfig.Fields 'new
.Item(sch & "sendusing") = 2 ' cdoSendUsingPort 'new
.Item(sch & "smtpserver") = "localhost" 'new (add your smtp server address here)
.update 'new
End With 'new

Set objMail = Server.CreateObject("CDO.Message")

Set objMail.Configuration = cdoConfig 'new
objMail.From = strFromEmail
objMail.To = strToEmail
objMail.Subject = Request("EmailSubject")
objMail.TextBody = strBody
objMail.Send

Set objMail = Nothing
Set cdoConfig = Nothing 'new