replyPUSH

Much like WordPress.com’s “Comment Reply via Email”, you can reply to any post you subscribe to.
Integrates with the wonderful <a href="https://wordpress.org/plugins/subscribe2/" title="subscribe2" rel="ugc">subscribe2</a> and <a href="http://replypush.com" title="replyPUSH.com" rel="nofollow ugc">replyPUSH.com</a> service to provide the email reply magic.
It automatically adds notifications for comment posts to keep the conversation flowing 🙂
All the subscriber need do, is reply at the top of their quoted email notification.

Reply By Email

Allows your users to reply to articles / blog posts and comments via email.

Jeroen Peters

WordPress plugin which makes bbPress show the newest replies first in all forums

Newest replies first in bbPress

WordPress plugin which makes bbPress show the newest replies first in all forums.

Reply By Email vs Newest replies first in bbPress