Adding Haraka to SMTP servers.

README.md

@@ -276,6 +276,7 @@ Comparison of NoSQL servers: http://kkovacs.eu/cassandra-vs-mongodb-vs-couchdb-v
 *SMTP servers.*
 
 * [Exim](http://www.exim.org/) - Message transfer agent (MTA) developed at the University of Cambridge.
+* [Haraka](http://haraka.github.io/) - A high-performance, pluginable SMTP server written in JavaScript.
 * [OpenSMTPD](https://opensmtpd.org/) - Secure SMTP server implementation from the OpenBSD project.
 * [Postfix](http://www.postfix.org/) - Fast, easy to administer, and secure Sendmail replacement.
 * [Qmail](http://cr.yp.to/qmail.html) - Secure Sendmail replacement.