-Has the mail ever worked in the past?
-Have you verified you have the settings for you email system correct?
-Have you ensured the account you are using has sufficient privilege to send emails through SMTP/IIS Mail?
-What mail settings have you chosen (IIS Mail, SMTP)? Are you using the correct ports (due you need SSL ports?)
-Has your mail admin turned on redirect of mail?
Insanity: doing the same thing over and over again and expecting different results