code: @Override
  	protected void doExecute() {
  		Predicate<MailMessage> condition = createMessagePredicate();
  		List<MailMessage> messages = mailService.findMessages(accountReservationKey, condition, getExpectedMessagesCount());
  		validateMessages(messages);
  	}
docs: Retrieves a list of e-mail messages matching the patterns specified in the constructor. If
  the messages are successfully retrieved, they are passed to {@link #validateMessages(List)}
  for further validation.