I need recommendation for a good library for email (PM) and task management on a per-user basis. So far I've only come across Hoodie but it seems to be in beta and people are having trouble getting it running on Heroku.<p>I'm thinking about using the library on Heroku + Node.js backend and AngularJS front-end.<p>I really don't want to go solo and do something like a Haraka setup with MongoDB (or resque etc.)... it's cool as a side project but I'd rather use a library that's been tested by the community. Plus I don't need a full-fledged email service -- just private message capability that can be managed with minimum effort.