Работа с почтой

#apptype windows
#reference 'System.Windows.Forms.dll'
#reference 'System.Drawing.dll'
uses
  System.Net,
  System.Net.Mail,
  System.Net.Mime,
  System.Windows.Forms,
  System.Drawing;
 
var
  SM: Form;
  SMTPserver, mail, pass, ToReceiver, body: string;
  Message: MailMessage;
  button: Button;
  tb1, tb2, tb3, tb4, tb5: TextBox;
  tx1, tx2, tx3, tx4, tx5, tx6: System.Windows.Forms.Label;
  cb: ComboBox;
  Font1 := new Font(new FontFamily('Times New Roman'), 12);
  Font2 := new Font(new FontFamily('Times New Roman'), 26);
  
procedure buttonClick(sender: object; args: System.EventArgs);
begin
if cb.Text = 'Yandex' then SMTPserver:= 'smtp.yandex.ru';
if cb.Text = 'Gmail' then SMTPserver:= 'smtp.gmail.com';
if cb.Text = 'Rambler' then SMTPserver:= 'smtp.rambler.ru';
  mail := tb3.Text;
  pass := tb4.Text;
  ToReceiver := tb5.Text;
  body := tb2.Text;
  var fromSender := tb3.Text;
  var subject := tb1.Text;
  var mailClient := new SmtpClient(SMTPserver, 25);
  mailClient.Credentials := new NetworkCredential(mail, pass);
  message := MailMessage.Create(fromSender, toReceiver, subject, body);
  Message.IsBodyHtml := False;
  mailClient.Send(message);
  message.Dispose;
end;
  
begin
  
  tb1 := new TextBox;
  tb1.Top := 20;
  tb1.Width := 594;
  tb1.Font := Font1;
  
  tb2 := new TextBox;
  tb2.Multiline := True;
  tb2.Top := 65;
  tb2.Height := 350;
  tb2.Width := 594;
  tb2.Font := Font1;
  
  tb3 := new TextBox;
  tb3.Top := 420;
  tb3.Left := 80;
  tb3.Width := 200;
  tb3.Font := Font1;
  
  tb4 := new TextBox;
  tb4.Top := 420;
  tb4.Left := 380;
  tb4.Width := 200;
  tb4.PasswordChar := '*';
  tb4.Font := Font1;
  
  tb5 := new TextBox;
  tb5.Top := 450;
  tb5.Left := 132;
  tb5.Width := 200;
  tb5.Font := Font1;
  
  tx1 := new System.Windows.Forms.Label;
  tx1.Height := 25;
  tx1.Width := 148;
  tx1.Text := 'Тема сообщения:';
  tx1.Font := Font1;
  
  tx2 := new System.Windows.Forms.Label;
  tx2.Top := 45;
  tx2.Height := 25;
  tx2.Width := 154;
  tx2.Text := 'Текст сообщения:';
  tx2.Font := Font1;
  
  tx3 := new System.Windows.Forms.Label;
  tx3.Top := 422;
  tx3.Height := 25;
  tx3.Width := 100;
  tx3.Text := 'Ваш e-mail:';
  tx3.Font := Font1;
  
  tx4 := new System.Windows.Forms.Label;
  tx4.Top := 422;
  tx4.Left := 290;
  tx4.Height := 25;
  tx4.Width := 100;
  tx4.Text := 'Ваш пароль:';
  tx4.Font := Font1;
  
  tx5 := new System.Windows.Forms.Label;
  tx5.Top := 452;
  tx5.Height := 25;
  tx5.Width := 140;
  tx5.Text := 'E-mail получателя:';
  tx5.Font := Font1;
  
  tx6 := new System.Windows.Forms.Label;
  tx6.Top := 480;
  tx6.Height := 25;
  tx6.Width := 238;
  tx6.Text := 'Выберите хостинг Вашей почты:';
  tx6.Font := Font1;
  
  cb := new ComboBox;
  cb.Left := 238;
  cb.Top := 480;
  cb.Width := 100;
  cb.Items.Add('Yandex');
  cb.Items.Add('Gmail');
  cb.Items.Add('Rambler');
  
  button := new System.Windows.Forms.Button;
  button.Top := 510;
  button.Width := 594;
  button.Height := 50;
  button.Text := 'Отправить';
  button.Click += buttonClick;
  button.Font := Font2;
  
  SM := new Form;
  SM.StartPosition := FormStartPosition.CenterScreen;
  SM.FormBorderStyle := FormBorderStyle.FixedSingle;
  SM.MaximizeBox := False;
  SM.Text := 'SendMessage';
  SM.Width := 600;
  SM.Height := 592;
  
  SM.Controls.Add(tb1);
  SM.Controls.Add(tb2);
  SM.Controls.Add(tb3);
  SM.Controls.Add(tb4);
  SM.Controls.Add(tb5);
  SM.Controls.Add(tx1);
  SM.Controls.Add(tx2);
  SM.Controls.Add(tx3);
  SM.Controls.Add(tx4);
  SM.Controls.Add(tx5);
  SM.Controls.Add(tx6);
  SM.Controls.Add(cb);
  SM.Controls.Add(button);
  
  Application.EnableVisualStyles;
  
  Application.Run(SM);
 
end.