procedure SendenThreadExecute;
    var tp: PThreadParams;
        Thread: THandle;
        ExitCode: Cardinal;
        ec: DWORD;
        ThreadID: Cardinal;
    begin

    if Length(MailForm.SubjectEdit.Text) >= 3 then
      begin

      New(tp);

      with Mailform.IdMsgSend do
          begin
            Body.Assign(Mailform.ContentMemo.Lines);
            From.Text := UserEmail;
            ReplyTo.EMailAddresses := UserEmail;
            Recipients.EMailAddresses := ReceiverEmail; { To: header }
            Subject := Mailform.SubjectEdit.Text; { Subject: header }
            Priority := TIdMessagePriority(Mailform.PrioComboBox.ItemIndex); { Message Priority }
          end; // with

      Mailform.SMTP.Username := SmtpServerUser;
      Mailform.SMTP.Password := SmtpServerPassword;

      {Allgemeine Einstellungen}
      Mailform.SMTP.Host := SmtpServerName;
      Mailform.SMTP.Port := SmtpServerPort;

      tp.sttemp := Mailform.EingangStatusBar.Panels[1].Text;
      Mailform.Label1.Caption := tp^.sttemp;
      tp.msgSend := Mailform.IdMsgSend;
      Thread := BeginThread(nil, 0, @SendenThreadFunction, tp, 0, ThreadID);
        // Auf Beendigung des Threads warten.
      //WaitForSingleObject(Thread, INFINITE);
      CloseHandle(Thread);
      end //if
    else
      begin
        MessageDlg('Bitte geben Sie einen Betreff ein.', mtWarning ,[mbOK],0);
      end;
    end;

  function SendenThreadFunction(tp: PThreadParams): Integer;
  var msgSend: TIdMessage;
      sttemp: String;
  begin
    sttemp := PThreadParams(tp)^.sttemp;
    msgSend := PThreadParams(tp)^.msgSend;
    {Mail verschicken}
    Mailform.ShowStatus('Verbindung mit Postausgangsserver wird hergestellt...');
    Mailform.SMTP.Connect;

    try
      Mailform.SMTP.Send(msgSend);
      Mailform.ShowStatus('Nachricht wird gesendet');
    finally
      Mailform.SMTP.Disconnect;
      Mailform.ShowStatus(sttemp);
      Mailform.MailPb.Visible := False;
      Mailform.MailPb.Position := Mailform.MailPb.Max;
      Mailform.EingangStatusBar.Panels[0].Text := 'Senden erfolgreich';
      Dispose(tp);
    end; // try