asp.net 发送邮件

 System.Web.Mail.MailMessage email = new System.Web.Mail.MailMessage();

                    email.From = "noreply@xxx.xx";
                    if (ccemail) email.Cc ="cc@xx.com";
                    email.To ="email@xx.com";

                    email.Subject = title;
                    email.BodyFormat = System.Web.Mail.MailFormat.Html;
                    email.Body = content;

                    SmtpClient smtp = new SmtpClient();

                    Configuration configurationFile = WebConfigurationManager.OpenWebConfiguration("~/");
                    MailSettingsSectionGroup msg = configurationFile.GetSectionGroup("system.net/mailSettings") as MailSettingsSectionGroup; 
                   
                    string username = msg.Smtp.Network.UserName.ToString();
                    string password = msg.Smtp.Network.Password.ToString();
                    string smtpurl = msg.Smtp.Network.Host.ToString();
                    System.Web.Mail.SmtpMail.SmtpServer = smtpurl;

                    email.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1");
                    email.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", username);

                    email.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", password);

                    System.Web.Mail.SmtpMail.Send(email);