[embed_url: https://raw.githubusercontent.com/panticz/installit/master/install.dovecot.sh]

/etc/dovecot/conf.d/10-master.conf
  inet_listener imaps {
    port = 993
    ssl = yes
  }

openssl req -new -x509 -nodes -out /etc/dovecot/dovecot.pem -keyout /etc/dovecot/private/dovecot.pem -days 1095 -newkey rsa:4096

Links
http://wiki2.dovecot.org/SSL/DovecotConfiguration
http://wiki2.dovecot.org/SSL/CertificateCreation
http://ebalaskas.gr/wiki/dovecot/DovecotSSL
http://wiki.ubuntuusers.de/Dovecot
https://help.ubuntu.com/11.04/serverguide/C/dovecot-server.html
http://wiki.dovecot.org/MainConfig
http://www.howtoforge.com/dovecot_mail_server_sieve_virtual_users