Re: bbpress + mailman integration
This plugin should send all moderators/admins an email whenever a post is made by any non-moderator/admin:
https://bbpress.org/plugins/topic/moderator-new-post-notification/
Or alternatively, this one should hold all posts in moderation until a moderator/admin has approved it:
https://bbpress.org/plugins/topic/bb-moderation-hold/
Hope one of those does the trick for you!