Jared Atchison

This plugin is for bbPress 2.x
Many people who run forums would like to know when a new topic (thread) has been posted but do not have the time to constantly check their forum for activity. This solves that!
This plugin will send an e-mail notification to specific addresses when a new topic has been posted. The users who receive notification along with a simple e-mail template is configured in the bbPress settings.
See the <a href="http://www.jaredatchison.com/2011/08/28/bbpress-new-topic-notifications/" rel="nofollow ugc">author website</a>.

bbPress New Topic Notifications

Send notification emails to specific users when a new bbPress topic is posted.

BuddyDev

Brajesh Singh

bbPress Notify Admin plugin notifies all the admins when a new topic is created or a new reply is posted on bbPress forum. It needs bbPress 2.2 or above. 
We use this plugin internally at BuddyDev to provide timely support.
For more details, please visit <a href="https://buddydev.com/bbpress/introducing-bbpress-notify-admins-plugin-notify-admins-on-new-topics-or-new-replies" rel="nofollow ugc">BuddyDev.com</a>
For support, please use <a href="https://buddydev.com/support/forums/" rel="nofollow ugc">BuddyDev Forums</a>.

bbPress Notify Admins

bbPress Notify Admins plugin notifies all site admins when a new topic is created or a new reply is posted on the bbPress based forums.

bbPress New Topic Notifications vs bbPress Notify Admins