This discourse installation is a pilot to test the configuration.
This is category “Sandbox”. The intention is to find a mailman mailing list to test synchronization with or a bridge between that test mailing list and this discourse installation. The preferred set up will be that messages from the test mailing list will end up in the test category.
In your settings you can change preferences for watching items in this category. For example tick a box to stop receiving notifications of posts in this category.
You’re helpful by providing feedback. Is it easy or not to mute posts from a certain category?