tl;dr please improve “mailing list mode” (especially better signal-to-noise in mesages)
First of all, I want to be clear that I appreciate the value that discourse brings and that it has some significant strengths. I also soundly recognize that many folks prefer the sort of communication medium that discourse provides. A diverse community is a healthy one. 
A number of discussions have happened related to discourse vs. mailing lists. Most recently the topic came up at the (online-only) language summit. Some folks would still rather use email as their medium for discussions (me included), for various reasons. Discourse provides a mailing list mode which seems like it should satisfy those folks. Unfortunately, it mostly doesn’t.
Signal-to-Noise
The main problem: the resulting emails are too noisy. At least that was the main sentiment from the above group of people, from what I understood. Personally, I find the messages to be cluttered and to make it hard to quickly identify the actual message. The (visual?) signal-to-noise ratio is poor, and definitely worse than in the discourse UI. For comparison, here is an example of what I get (visually) vs. what I would hope for:
vs.
On Mon, Apr 6, 2020 at 9:01 PM Gregory P. Smith <python1@discoursemail.com> wrote:
> As I expect people expect: We’re in “no Events” mode until further notice.
> Intentionally non-specific, but it seems realistic to me to plan for this to mean
> it will be 18 months until international and domestic travel population mixing
> events can be held again. Anywhere in the world. I’m still dow…
I will start a new thread and see how I can help.
Or a concrete example of the sort of message I’m used to:
Other Concerns
A few other concerns have been brought up, but they are less broadly expressed.
One such concern is the flat nature of conversations in discourse. From what I understand, this flatness extends to the messages produced by mailing-list mode. So mail/nntp clients and list archives won’t reflect the tree nature of conversation threads.
Another noted concern: Mailing-list mode messages are not archived in any mailman 3 instance, so they are not discoverable (nor searchable) there. That means having 2 different places to check.
