title: TSendMail.Execute Returns True Without Sending
body: <p>If I understand correctly, TSendMail is supposed to use my installed email client. If I execute it on my virtual machine, it returns "true" and gives me the expected message that I need to install an email program.</p>
  
  <p>However, if I run the program on my regular machine (on which Thunderbird is installed) TSendMail.execute returns "True", but Thunderbird doesn't get called. Here's my code:</p>
  
  <pre><code>procedure TfSendEmail.btnSendClick(Sender: TObject);
  var
    aNode: PVirtualNode;
    Data: PRecipients;
    i: integer;
  begin
    aNode := vstRecipients.GetFirst;
    i := 0;
    while (aNode &lt;&gt; nil) do
    begin
      Data := vstRecipients.GetNodeData(aNode);
      Mail.Recipients.Add;
      Mail.Recipients[i].DisplayName := Data.Name;
      Mail.Recipients[i].Address := Data.Email;
      inc(i);
      aNode := vstRecipients.GetNext(aNode);
    end;
  
    Mail.Attachments.Assign(lbAttachments.Items);
  
    Mail.Subject := edtSubject.Text;
  
    Mail.Text.Assign(mmoMsgText.Lines);
  
    if Mail.Execute then
    begin
      ShowMessage('Succeeded');
      //ModalResult := mrOk;
    end
    else
      MessageDlg('Sorry!. Could not send email.', mtError, [mbOK], 0);
  end;
  </code></pre>
  
  <p>Using Delphi 10.2.3 on fully updated Win10 machines. Maybe my recipient assignment is faulty. Anyway, I can't find any complete usage examples, only the incomplete example on attachments from Embarcadero's wiki.</p>