The example represents a simple POP3 client, which can connect to a POP3 server, list available Emails within a mailbox, and download the selected message content. The program extracts MIME message parts, including text, HTML, and headers.

 

 

procedure TForm1.btnCheckMailClick(Sender: TObject);
var
  i, count: Integer;
begin
  if clPOP31.Active then Exit;

  clPOP31.Server := edtPop3Server.Text;
  clPOP31.UserName := edtUser.Text;
  clPOP31.Password := edtPassword.Text;

  clPOP31.Open();
  try
    lbMessages.Items.Clear();

    count := clPOP31.MessageCount;
    for i := 1 to count do
    begin
      clPOP31.RetrieveHeader(i, clMailMessage1);
      if (clMailMessage1.Subject = '') then
      begin
        lbMessages.Items.Add(clMailMessage1.From.FullAddress);
      end else
      begin
        lbMessages.Items.Add(clMailMessage1.Subject);
      end;
    end;
  finally
    clPOP31.Close();
  end;

  ShowMessage(Format('Collecting completed, %d messages in the mailbox', [count]));
end;

procedure TForm1.lbMessagesDblClick(Sender: TObject);
var
  dlg: TMessageForm;
begin
  if clPOP31.Active or (lbMessages.ItemIndex < 0) then Exit;

  clPOP31.Server := edtPop3Server.Text;
  clPOP31.UserName := edtUser.Text;
  clPOP31.Password := edtPassword.Text;

  clPOP31.Open();
  dlg := TMessageForm.Create(nil);
  try
    clPOP31.Retrieve(lbMessages.ItemIndex + 1, clMailMessage1);

    dlg.edtFrom.Text := clMailMessage1.From.FullAddress;
    dlg.edtTo.Text := clMailMessage1.ToList.EmailAddresses;
    dlg.edtSubject.Text := clMailMessage1.Subject;

    dlg.memBody.Lines := clMailMessage1.MessageText;

    dlg.ShowModal();
  finally
    dlg.Free();
    clPOP31.Close();
  end;
end;