为什么不能发送邮件提示：‘bad sequence of commands’

为什么不能发送邮件提示：‘bad sequence of commands’
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, IdMessage, IdBaseComponent, IdComponent,
  IdTCPConnection, IdTCPClient, IdMessageClient, IdSMTP;type
  TForm1 = class(TForm)
    IdSMTP1: TIdSMTP;
    IdMessage1: TIdMessage;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
idmessage1.Clear;
idmessage1.Subject:='daring';
idmessage1.Body.Add('test');
//idmessage1.From.Text:='[email protected]';
idmessage1.From.Address:='[email protected]';
//idmessage1.From.Name:='[email protected]';
idmessage1.Recipients.EMailAddresses:='[email protected]';
//idmessage1.ReceiptRecipient.Text:='';
idsmtp1.Host:='smtp.126.com';
idsmtp1.AuthenticationType:=atLogin;
idsmtp1.Username:='daring';
idsmtp1.Password:='*****';//邮箱密码
idsmtp1.Port:=25;
try
idsmtp1.Connect();
idsmtp1.Send(idmessage1);
showmessage('OK！');
except
showmessage('无法连接到服务器！');
exit;
end;
end;end.