C# Sending Email Problem

Hi everyone,
I using C# to created a sending email system.
Now i want to retreive data (email) from microsoft excel and put into
                MailMessage mail = new MailMessage();
                mail.To.Add("<here>");
                mail.From = new MailAddress("xxx@xxx.com");
                mail.Subject = "";
any idea?
Thks in advance,
Nasri
...