Personally we wouldn’t have selected discourse without this feature. My field sales teams used to be on a Google group, we split that group into multiple sub-categories owned by the product manager for that feature. Allowing them to answer via email was the norm, it reduces friction considerably and also serves as a reminder to check in on the community.
However, I haven’t published addresses to start conversations via email except on the internal side. I still want our end users coming to the community to start a question, that way the search and suggested titles can help solve the issue.