Merge branch 'master' of https://github.com/jcherqui/awesome-sysadmin into merge-patches

README.md

@@ -392,6 +392,7 @@ Comparison of NoSQL servers: http://kkovacs.eu/cassandra-vs-mongodb-vs-couchdb-v
 * [Postfix](http://www.postfix.org/) - Fast, easy to administer, and secure Sendmail replacement.
 * [Qmail](http://cr.yp.to/qmail.html) - Secure Sendmail replacement.
 * [Sendmail](http://www.sendmail.com/sm/open_source/) - Message transfer agent (MTA).
+* [Mail-in-a-Box](https://mailinabox.email/) - Take back control of your email with this easy-to-deploy mail server in a box.
 
 ## Software Containers
 *Operating system–level virtualization.*