Discourse? It has a built-in "mailing list mode" that acts like a mailing list, but it also has a readable web archive, and you can pay them to host it for you.

Discourse? It has a built-in "mailing list mode" that acts like a mailing list, but it also has a readable web archive, and you can pay them to host it for you. https://discourse.org/ https://discourse.org/