code: public void deleteMessages(final String accountReservationKey) {
  		MailAccount mailAccount = checkNotNull(mailAccountManager.lookupUsedMailAccountForCurrentThread(accountReservationKey),
  				"No mail account reserved for current thread under key '%s'", accountReservationKey);
  		storeManagerFactory.create(mailAccount).deleteAllMessages();
  	}
docs: Deletes all messages from the mail account reserved under the specified
  {@code accountReservationKey}.
  
  @param accountReservationKey
  the key under which the account has been reserved