We're building a set of Ansible roles for self-hosting services with a complete mailserver based on dovecot and postfix. See https://wiki.base48.cz/Nestihacky and https://github.com/nestihacky/ansible-role-mailserver for more details. Originally inspired by https://github.com/sovereign/sovereign/ but with focus on Centos/Fedora (due to SELinux) and re-usability (separate Ansible roles).