Package cyrus-imapd: Information

The Cyrus IMAP (Internet Message Access Protocol) server provides
access to personal mail, system-wide bulletin boards, news-feeds,
calendar and contacts through the IMAP, NNTP, CalDAV and CardDAV
protocols. The Cyrus IMAP server is a scalable enterprise groupware
system designed for use from small to large enterprise environments
using technologies based on well-established Open Standards.

A full Cyrus IMAP implementation allows a seamless mail and bulletin
board environment to be set up across one or more nodes. It differs
from other IMAP server implementations in that it is run on "sealed
nodes", where users are not normally permitted to log in. The mailbox
database is stored in parts of the filesystem that are private to the
Cyrus IMAP system. All user access to mail is through software using
the IMAP, IMAPS, POP3, POP3S, KPOP, CalDAV and/or CardDAV protocols.