If you are using a Windows 2000 / 2003 Server, or even XP Pro chances are that CDOSYS is your best bet for sending email from Active Server Pages. That is because CDOSYS is installed on all of them by default. Gone are the days of using CDONTS which was the old way of sending email from ASP. CDOSYS is it’s replacement.
As you should know, on Windows 2003 Server, CDONTS was deprecated and CDOSYS is the new one Microsoft email sender component (read more on Microsoft Website)
However, some ASP scripts will require CDONTS and customers can need CDONTS install.So, to install CDONTS
1) First, install MailEnable or other SMTP server. Make sure it is running.
2) Download and unzip cdonts.dll to C:WindowsSystem32 folder
3) Register the CDONTS.DLL component on your server by clicking start >> run >> type :
regsvr32 c:winntsystem32cdonts.dll >> ENTER
Now CDONTS should being work perfectly.
To know if CDONTS is installed you can use http://www.pensaworks.com/prg_com.asp to view a list of installed components.A