https://github.com/discourse/discourse
一个免费开源的优秀论坛系统. 邮件方面也做的很不错.
Built With: Ruby on Rails | Ember.js | PostgreSQL | Redis

安装指南:
https://github.com/discourse/discourse/blob/master/docs/INSTALL-cloud.md

GitHub

GitHub - discourse/discourse: A platform for community discussion. Free, open, simple.

A platform for community discussion. Free, open, simple. - discourse/discourse