Haraka - a Node.js mail server

Has anyone used this enough to tell me why it'd be a better pick than Lamson (http://lamsonproject.org/)? Web servers, unlike web servers, don't strike me as an arena where async is very useful.

This is fantastic, I was just looking for a way to turn incoming emails into Resque jobs for a weekend project without having to mess with postfix mail filters, and I was just about to resort to paying for SendGrid.

Nice. Looks like a Node.js port of qpsmtpd - http://smtpd.develooper.com/

Edit: Just found that author has noted that Haraka is quite similar to Qpsmtpd.

node.js is Evented I/O. It might not be a perfect match for mail server. Not like in Comet or other similar situations, SMTP sessions are highly batched and not that human-interactive. There might be very little inactive open connections on a typical mail server.

But based on document, "Haraka's primary purpose is to provide you with a much easier to extend mail server than most available SMTP servers out there such as Postfix, Exim or Microsoft Exchange, yet while still running those systems for their excellent ability to deliver mail to users."

Very cool. Seems a bit confusing though, how is a simple SMTP forwarder client configured? Something similar to msmtp?