system environment/daemons
- courier-authlib - Courier authentication library
- courier-authlib-ldap - LDAP support for the Courier authentication library
- courier-authlib-mysql - MySQL support for the Courier authentication library
- courier-authlib-pgsql - MySQL support for the Courier authentication library
- courier-authlib-pipe - External authentication module that communicates via pipes
- courier-authlib-userdb - userdb support for the Courier authentication library
- pound - pound is a reverse proxy, load balancer and HTTPS front-end