Then you might want to check out Talkyard, it is chat + forum. https://www.talkyard.io (I'm developing it). A bit like a Slack, HN, Discourse hybrid. Post-by-email is planned.
Looking good, but please, don't make me click on the small area that is the title of a post to see the content.
Ok, thanks for the feedback. (You had in mind the topic titles, in the topic list, right? And you'd prefer the text excerpt, below a topic title, to also be clickable and link to the topic, right?)
the best will be chat+forum, and support mailing list style digest, also support post-by-email