Discourse, the forum software that runs Clojureverse, has all the features of a mailing list.
To receive all posts in a certain category in your mailbox, visit the category page (e.g. /c/meta), click the circle in the top right corner, and set it to “Watching”. You can reply to these emails to post a response.
To post to a category, use the category name you can see it in the URL, e.g. meta, and add @lists.clojureverse.org. For example, you can create a new post in the Chestnut forum by sending an email to chestnut@lists.clojureverse.org.