Apache, imap, and exim all support ssl connections. Because I want webmail connections to be encrypted, so that passwords are not sent over the internet in plain text, I needed to create a key and a certificate for apache. For testing purposes I am going to be my own certificate authority. This will most likely be changed for the production server. You don't have to use any certificate authority - see http://www.tldp.org/HOWTO/SSL-RedHat-HOWTO.html