This server provides POP3 access to Maildir format mailboxes. It does
not handle traditional mailbox files.

It is part of the Courier mail server (http://www.courier-mta.org) but
can be configured as a standalone POP3 server.

Features include an extremely small memory footprint, abstract
authentication modules (e.g. /etc/passwd, LDAP, PAM), virtual mailbox
support, resource controls, SSL/TLS, and IPv6 support.
