Good JS library for email (PM) and task management?

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.

I'm thinking about using the library on Heroku + Node.js backend and AngularJS front-end.

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.