// Test getMailSendMock and isMailSendMock
        assertEquals("true", fessEnv.getMailSendMock());
        assertTrue(fessEnv.isMailSendMock());

        // Test getMailSmtpServerMainHostAndPort
        assertEquals("localhost:25", fessEnv.getMailSmtpServerMainHostAndPort());

        // Test getMailSubjectTestPrefix
        assertEquals("[Test]", fessEnv.getMailSubjectTestPrefix());

        // Test getMailReturnPath