When you or a fellow teammate (admin) comments on a post, people who have voted will get a custom-branded email like this:
Note: There is an unsubscribe link at the bottom if they wish to stop receiving updates like these.
Users can just click the "View Post" button to add any comments. Replying to the email directly will not automatically add to the post. Users who do so will be directed to contact you directly.
Give details about the progress of the feature
Show screenshots of the feature to get people excited and ensure you're on the right track. Your users will love being involved in the process.
Get more feedback
Now you can reach out to interested parties when you have further questions. What exactly is your user trying to solve? Does something else solve that problem?