Dovecot is an IMAP and POP3 server for Linux/UNIX-like systems, written
with security primarily in mind.  Although it's written in C, it uses
several coding techniques to avoid most of the common pitfalls.  Dovecot
can work with standard mbox and maildir formats and it's fully 
compatible with UW-IMAP and Courier IMAP servers as well as mail clients
accessing the mailboxes directly.

Flavors:
          bdb - Build with Berkeley DB support for a dictionary store
         ldap - Build with LDAP support as an authentication source
        mysql - Build with MySQL support as an authentication source
   postgresql - Build with PostgreSQL support as an authentication source
       sqlite - Build with SQLite support as an authentication source