Dovecot for Red Hat Enterprise is an open source IMAP and POP3 server for Linux or UNIX-like systems, written with security primarily in mind. Dovecot is an excellent choice for both small and large installations. It requires no special administration and it uses very little memory. Dovecot is the IMAP servers while still supporting the standard mbox and Maildir formats. The mailboxes are transparently indexed, which gives Dovecot its good performance while still providing full compatibility with existing mailbox handling tools.