using System.Web.Mail;


MailMessage mail = new MailMessage();
mail.From =  "info@site.com" ;
mail.To =  "user@mail.ru" ;
mail.Subject =  "Email from ASP.NET" ;
mail.Body =  "this is the mail message sent by asp.net" ;
mail.BodyFormat = MailFormat.Html;
SmtpMail.SmtpServer =  "localhost" ;
SmtpMail.Send(mail);