Dovecot というソフトウェアを使用して、受信メールサーバを構築します。
環境
CentOS 7.2.X
Dovecot 2.2.X
1.Dovecotのインストール
Dovecotをインストールします。
[root@ ~]# yum -y install dovecot
2.Dovecotの設定ファイル編集（dovecot.conf）
設定ファイル/etc/dovecot/dovecot.confを編集します。
[root@ ~]# vi /etc/dovecot/dovecot.conf
「protocols = imap pop3 lmtp」の行頭に#を追加し、この行を無効にして、その下に「protocols = imap pop3」を追加します。
「listen = *, ::」の行頭に#を追加し、この行を無効にして、その下に「listen = *」を追加します。
## Dovecot configuration file
# If you're in a hurry, see http://wiki2.dovecot.org/QuickConfiguration
# "doveconf -n" command gives a clean output of the changed settings. Use it
# instead of copy&pasting files when posting to the Dovecot mailing list.
# '#' character and everything after it is treated as comments. Extra spaces
# and tabs are ignored. If you want to use either of these explicitly, put the
# value inside quotes, eg.: key = "# char and trailing whitespace "
# Most (but not all) settings can be overridden by different protocols and/or
# source/destination IPs by placing the settings inside sections, for example:
# protocol imap { }, local 127.0.0.1 { }, remote 10.0.0.0/8 { }
# Default values are shown for each setting, it's not required to uncomment
# those. These are exceptions to this though: No sections (e.g. namespace {})
# or plugin settings are added by default, they're listed only as examples.
# Paths are also just examples with the real defaults being based on configure
# options. The paths listed here are for configure --prefix=/usr
# --sysconfdir=/etc --localstatedir=/var
# Protocols we want to be serving.
#protocols = imap pop3 lmtp
protocols = imap pop3
# A comma separated list of IPs or hosts where to listen in for connections.
# "*" listens in all IPv4 interfaces, "::" listens in all IPv6 interfaces.
# If you want to specify non-default ports or anything more complex,
# edit conf.d/master.conf.
#listen = *, ::
listen = *
# Base directory where to store runtime data.
#base_dir = /var/run/dovecot/
3.Dovecotの設定ファイル編集（10-mail.conf）
設定ファイル/etc/dovecont/conf.d/10-mail.confを編集します。
[root@ ~]# vi /etc/dovecot/conf.d/10-mail.conf
「mail_location = maildir:~/Maildir」を追加します。
## ## Mailbox locations and namespaces ## # Location for users' mailboxes. The default is empty, which means that Dovecot # tries to find the mailboxes automatically. This won't work if the user # doesn't yet have any mail, 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 # kept. 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/wiki/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 # # <doc/wiki/MailLocation.txt> # #mail_location = mail_location = maildir:~/Maildir
4.Dovecotの設定ファイル編集（10-auth.conf）
設定ファイル/etc/dovecot/conf.d/10-auth.confを編集します。
[root@ ~]# vi /etc/dovecot/conf.d/10-auth.conf
「disable_plaintext_auth = no」を追加します。
## ## Authentication processes ## # Disable LOGIN command and all other plaintext authentications unless # SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP # matches the local IP (ie. you're connecting from the same computer), the # connection is considered secure and plaintext authentication is allowed. # See also ssl=required setting. #disable_plaintext_auth = yes disable_plaintext_auth = no
5.Dovecotの設定ファイル編集（10-ssl.conf）
設定ファイル/etc/dovecont/conf.d/10-ssl.confを編集します。
[root@ ~]# vi /etc/dovecont/conf.d/10-ssl.conf
SSLを使用しないので、「ssl = no」にします。
## ## SSL settings ## # SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt> # disable plain pop3 and imap, allowed are only pop3+TLS, pop3s, imap+TLS and imaps # plain imap and pop3 are still allowed for local connections ssl = no
6.Dovecotの起動と自動起動設定
[root@ ~]# systemctl start dovecot [root@ ~]# systemctl enable dovecot
Dovecotの設定は以上です。
7.PostfixとDovecotの通信許可
PostfixとDovecotの通信を許可します。
送信ポート（25・587）、POP受信ポート（110）、IMAP受信ポート（143）を許可設定します。
設定を反映させるため、必ずリロードします。
[root@ ~]# firewall-cmd --permanent --zone=public --add-port=25/tcp success [root@ ~]# firewall-cmd --permanent --zone=public --add-port=587/tcp success [root@ ~]# firewall-cmd --permanent --zone=public --add-port=110/tcp success [root@ ~]# firewall-cmd --permanent --zone=public --add-port=143/tcp success [root@ ~]# firewall-cmd --reload success
8.メール専用ユーザの追加
PostfixとDovecotの設定が完了したので、メール専用ユーザを追加します。
※例として、testuserを追加します。
[root@ ~]# useradd -s /sbin/nologin testuser [root@ ~]# passwd testuser Changing password for user testuser. New UNIX password: （パスワード入力） Retype new UNIX password: （パスワード確認） [root@ ~]# echo '（パスワード入力）' | saslpasswd2 -p -u mail.example.com -c testuser（SMTP-Auth用ユーザ・パスワードの登録） [root@ ~]# sasldblistusers2（SMTP-Auth用ユーザ名・パスワードの確認） testuser@mail.example.com: userPassword
下記のコマンドでsasldb2の所有グループをpostfixにします。※初回のみ
[root@ ~]# chgrp postfix /etc/sasldb2
メール専用ユーザの追加は以上です。