Yes, it's pretty focussed on mailing lists as alternative. Having a comment section may work too, but then, it shouldn't be hosted by discurs of course, and you have the trouble of managing it.
Same goes with your own forum, but it's not worth mentioning it almost, since nowadays everyone seems so opposed to a forum. But I believe, a good alternative for a mailing list is RSS (for the people who are tired of signing up for stuff).