Hi Ragze,
This is a very broad question, it could be done a number of ways, such as writing your own client in ASP.Net 2.0 (mirroring what Outlook does) or doing some sort of Service. As Dublin is a Hosting application, this is not the correct place to ask, I would try instead on the ASP.Net Forums (
http://www.asp.net) and be much more specific as to the requirements of the application that you want to build.
Regards,
Ed