用IdSMTP和IdMessage发送一个邮件，用户名或口令或邮件地址实际上是错的，但SMTP服务器的设置是正确的，可是send后不报错

Question

1.IdSMTP设置了错误的username或password或Address，正确的Host,但是connect不报错
2.IdSmtp.send(IdMessage)也不报错
3.bflag := IdSMTP1.Authenticate();报错，为什么？如何才能验证设置是错误的，邮件实际上没收到呢，我希望能检测出没收到邮件，而弹出一个错误框。谢谢。着急

Answer 1

//这是我在校时写过的一段,当时测试是可以发送的.
//"TIdAttachment.Create(IdMessage1.MessageParts,MailAttachmentEdit.Text);"这句是
//增加附件
procedure TForm11.BtnSendMailClick(Sender: TObject);
begin
    IdSMTP1.AuthenticationType:=atLogin;
    IdSMTP1.Host:=MailServerCombo.Text;
    IdSMTP1.Port:=25;
    IdMessage1.From.Address:=MailFromEdit.Text;
    IdSMTP1.Username:=MailUsernameEdit.Text;
    IdSMTP1.Password:=MailPasswordEdit.Text;    IdMessage1.Recipients.EMailAddresses:=MailToEdit.Text;    IdMessage1.Subject:=MailSubjectEdit.Text;
    IdMessage1.Body.Text:=MailBodyMemo.Text;    if FileExists(MailAttachmentEdit.Text) then
       TIdAttachment.Create(IdMessage1.MessageParts,MailAttachmentEdit.Text);
       
    try
      try
        BtnSendMail.Enabled:=false;
        IdSMTP1.Connect(1000);
        IdSMTP1.Send(IdMessage1);
        Application.MessageBox('您的邮件已经成功发送到目标邮箱！','成功',mb_ok+mb_iconinformation);
      except on E:Exception do
        StatusBar1.Panels[0].Text:=(E.Message);
      end;
    finally
      if IdSMTP1.Connected then
        IdSMTP1.Disconnect;
      BtnSendMail.Enabled:=True;
    end;
end;