c# Email verifier

I need a c# method that will expects and email address string and returns a status code on whether the Email is valid or not. The function should check the following: 1) Correct Email address syntax. 2) Verify the domain is a valid live domain with MX records. DNS check. 3) Verify the User exists at the domain. I believe this is done with an SMTP command. return 0 (Email address is valid) return 1 (invalid domain name) return 2 (User does not exist) The test interface can be a simple windows form or web page and must be done in VS 2005/c# or VS 2008/c# ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform c# VS 2005/2008