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

        // Test getMailReturnPath
        assertEquals("root@localhost", fessEnv.getMailReturnPath());
    }

    // Test custom properties
    public void xtest_customProperties() {
        // Create custom FessEnv with custom properties

            }

            @Override
            public String getMailFromName() {
                return "Fess Crawler";
            }

            @Override
            public String getMailReturnPath() {
                return "******@****.***";
            }

            @Override
            public Integer getCrawlerSystemMonitorIntervalAsInteger() {
                return 60000;
            }

            return "******@****.***";
        }

        @Override
        public String getMailFromName() {
            return "Fess System";
        }

        @Override
        public String getMailReturnPath() {
            return "******@****.***";
        }
    }

            return "******@****.***";
        }

        @Override
        public String getMailFromName() {
            return "Fess System";
        }

        @Override
        public String getMailReturnPath() {
            return "******@****.***";
        }
    }

                LogNotificationPostcard.droppedInto(postbox, postcard -> {
                    postcard.setFrom(fessConfig.getMailFromAddress(), fessConfig.getMailFromName());
                    postcard.addReplyTo(fessConfig.getMailReturnPath());
                    if (toAddresses.length > 0) {
                        stream(toAddresses).of(stream -> stream.map(String::trim).forEach(address -> {
                            postcard.addTo(address);

                CrawlerPostcard.droppedInto(postbox, postcard -> {
                    postcard.setFrom(fessConfig.getMailFromAddress(), fessConfig.getMailFromName());
                    postcard.addReplyTo(fessConfig.getMailReturnPath());
                    if (toAddresses.length > 0) {
                        stream(toAddresses).of(stream -> stream.map(String::trim).forEach(address -> {
                            postcard.addTo(address);