# yum -y install dovecot

設定ファイルの編集
# vi /etc/dovecot.conf
プロトコルを指定
# Protocols we want to be serving:
protocols = imap imaps pop3 pop3s

メールボックス(Maildir)を各ユーザのホームディレクトリに配置
*******************************************************************************************************
* dovecot Ver 1.0以上( 1.0 <= Ver )は、属性名「default_mail_env」が「mail_location」に変更されました。*
* バージョンは以下のコマンドで確認できます                                                            *
* # rpm -qa dovecot                                                                                   *
* dovecot-1.0-1.rc15.fc6                                                                              *
*******************************************************************************************************

【dovecot Ver 1.0未満( Ver < 1.0 )の場合】
# Default MAIL environment to use when it's not set. By leaving this empty
# dovecot tries to do some automatic detection as described in
# doc/mail-storages.txt. There's a few special variables you can use:
#
#   %u - username
#   %n - user part in user@domain, same as %u if there's no domain
#   %d - domain part in user@domain, empty if user there's no domain
#   %h - home directory
#
# You can also limit a width of string by giving the number of max. characters
# after the '%' character. For example %1u gives the first character of
# username. Some examples:
#
#   maildir:/var/mail/%1u/%u/Maildir
#   mbox:~/mail/:INBOX=/var/mail/%u
#   mbox:/var/mail/%d/%n/:INDEX=/var/indexes/%d/%n
#
default_mail_env = maildir:~/Maildir

【dovecot Ver 1.0以上( 1.0 <= Ver )の場合】
# Location for users' mailboxes. This is the same as the old default_mail_env
# setting. The default is empty, which means that Dovecot tries to find the
# mailboxes automatically. This won't work if the user doesn't have any mail
# yet, so you should explicitly tell Dovecot the full location.
#
# If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u)
# isn't enough. You'll also need to tell Dovecot where the other mailboxes are
# and where Dovecot can place its index files. This is called the "root mail
# directory", and it must be the first path given in the mail_location setting.
#
# There are a few special variables you can use, eg.:
#
#   %u - username
#   %n - user part in user@domain, same as %u if there's no domain
#   %d - domain part in user@domain, empty if there's no domain
#   %h - home directory
#
# See doc/variables.txt for full list. Some examples:
#
#   mail_location = maildir:~/Maildir
#   mail_location = mbox:~/mail:INBOX=/var/mail/%u
#   mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n
#
# http://wiki.dovecot.org/MailLocation
#
mail_location = maildir:~/Maildir

chrootユーザのディレクトリ
# ':' separated list of directories under which chrooting is allowed for mail
# processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too).
# This setting doesn't affect login_chroot or auth_chroot variables.
# WARNING: Never add directories here which local users can modify, that
# may lead to root exploit. Usually this should be done only if you don't
# allow shell access for users. See doc/configuration.txt for more information.
valid_chroot_dirs = /home


Dovecot Ver 1.0からは POP3 UIDL format が変わったらしい。
メールログ「/var/log/maillog」に以下が出力され、メーラより取得する事が出来ない。
Jun  8 21:31:38 fedora dovecot: POP3(linux): pop3_uidl_format setting is missing from config file
Jun  8 21:31:38 fedora dovecot: child 2741 (pop3) returned error 89

以下のコマンドを実施して バージョンが 1.0以上( 1.0 <= Ver )であれば、以下の変更が必要
# rpm -qa dovecot
dovecot-1.0-0.beta8.1.fc5

# vi /etc/dovecot.conf
  # POP3 UIDL format to use. You can use following variables:
  #
  #  %v - Mailbox UIDVALIDITY
  #  %u - Mail UID
  #  %m - MD5 sum of the mailbox headers in hex (mbox only)
  #  %f - filename (maildir only)
  #
  # If you want UIDL compatibility with other POP3 servers, use:
  #  UW's ipop3d         : %08Xv%08Xu
  #  Courier version 0   : %f
  #  Courier version 1   : %u
  #  Courier version 2   : %v-%u
  #  Cyrus (<= 2.1.3)    : %u
  #  Cyrus (>= 2.1.4)    : %v.%u
  #  Older Dovecots      : %v.%u
  #
  # Note that Outlook 2003 seems to have problems with %v.%u format which was
  # Dovecot's default, so if you're building a new server it would be a good
  # idea to change this. %08Xu%08Xv should be pretty fail-safe.
  #
  # NOTE: Nowadays this is required to be set explicitly, since the old
  # default was bad but it couldn't be changed without breaking existing
  # installations. %08Xu%08Xv will be the new default, so use it for new
  # installations.
  #
  #pop3_uidl_format = %08Xu%08Xv
pop3_uidl_format = %u

dovecotを起動する
# /etc/rc.d/init.d/dovecot start
Dovecot Imap を起動中:                                     [  OK  ]

起動時にdovecotを起動する
# chkconfig dovecot on
設定内容を確認
# chkconfig --list dovecot
dovecot         0:オフ  1:オフ  2:オン  3:オン  4:オン  5:オン  6:オフ