public void DeleteMessage_ValidMessageId_InvokesFakePopClientFactory()
        {
            // arrange
            _emailService = new EmailService(_stubEmailWatcherOptions, _fakePopClientFactory, _messageTranslator);

            // act
            _emailService.DeleteMessage("1");

            // assert
            Assert.IsTrue(_fakePopClientFactory.HasBeenInvoked);
        }
        public void DeleteMessage_NullMessageId_ThrowsException()
        {
            // arrange
            _emailService = new EmailService(_stubEmailWatcherOptions, _fakePopClientFactory, _messageTranslator);

            // act
            _emailService.DeleteMessage(null);

            // assert
        }