Enviar e-mail com autenticação

procedure TWebForm1.Button1_Click(sender: System.Object; e: System.EventArgs);
var
  Mail: System.Web.Mail.MailMessage;

  cdoBasic  : &Object;
  username  : String;
  pw         : string;
  mailServer : string;
//  sErro : String;
begin
    cdoBasic   := (1 as &Object);
    username   := ´xxx@yyyy.com.br´;//usuário
    pw         := ´yyyyy´;//senha
    mailServer := ´smtp.yyyy.com.br´;//endereço smtp


  Mail := MailMessage.create;
//  try
    with Mail do
     begin
      From       := tbxNome.Text + ´<´+ txtEmail.Text + ´>´;
      &To        := ´xxx@xxx.com.br´;//e-mail padrão para onde será enviada a msg
      Subject    := txtAssunto.Text;
      Body       := txtMsg.Text;
      BodyFormat := System.Web.Mail.MailFormat.Text;
     end;

    mail.Fields.Add(´http://schemas.microsoft.com/cdo/configuration/smtpauthenticate´, cdoBasic);
    mail.Fields.Add(´http://schemas.microsoft.com/cdo/configuration/sendusername´, username);
    mail.Fields.Add(´http://schemas.microsoft.com/cdo/configuration/sendpassword´, pw);
    mail.Fields.Add(´http://schemas.microsoft.com/cdo/configuration/smtpserver´, mailServer);
    mail.Fields.Add(´http://schemas.microsoft.com/cdo/configuration/smtpserverport´, ´25´);

      SmtpMail.SmtpServer := ´smtp.xxx.com.br´;//endereço smtp
      SmtpMail.Send(Mail) ;
//  except
//   on e: Exception do
//    MsgResult.Text := ´Error!´;

 // end;


end;