letsencrypt.org https://letsencrypt.org is a very nice service that offers free SSL certificates which are fully recognized by most (if not all) web browsers (https), mail servers (smtps) and client (pops & imaps), and can be used to even set up encryption for things like ejabberd (https://www.process-one.net/ejabberd).
There are a few things fairly well documented, but still needing a little more, so we're writing some notes here.