Dovecot是一个开源的IMAP和POP3服务器,适用于Linux / UNIX类系统,主要考虑安全性。 Timo Sirainen发起了Dovecot并于2002年7月首次发布.Dovecot开发人员主要致力于生产轻量,快速且易于设置的开源邮件服务器
在这篇文章中,我们将向您展示如何安装和配置Postfix和Dovecot,这是我们邮件系统的两个主要组件。
Postfix是一种开源邮件传输代理(MTA),一种用于发送和接收电子邮件的服务。Dovecot是一个IMAP / POP3服务器,在我们的设置中它还将处理本地交付和用户身份验证。
本教程是为Ubuntu 16.04编写的,但是相同的小修改步骤应适用于任何较新版的ubuntu。
前提条件
在继续本教程之前,请确保以具有sudo权限的用户身份登录。
安装Postfix和Dovecot
Ubuntu默认存储库中的Dovecot软件包已过时。为了可以使用imap_sieve
模块,我们将从Dovecot社区存储库安装Dovecot
使用以下wget命令将存储库GPG密钥添加到apt源密钥环:
wget -O- https://repo.dovecot.org/DOVECOT-REPO-GPG | sudo apt-key add -
使用以下命令启用Dovecot社区存储库:
echo "deb https://repo.dovecot.org/ce-2.3-latest/ubuntu/$(lsb_release -cs) $(lsb_release -cs) main" | sudo tee -a /etc/apt/sources.list.d/dovecot.list
sudo apt updatesudo debconf-set-selections <<< "postfix postfix/mailname string $(hostname -f)"sudo debconf-set-selections <<< "postfix postfix/main_mailer_type string 'Internet Site'"sudo apt install postfix postfix-mysql dovecot-imapd dovecot-lmtpd dovecot-pop3d dovecot-mysql
Postfix配置
我们将设置Postfix以使用虚拟邮箱和域
首先创建sql
配置文件,该文件将指示postfix如何访问Postfix Admin创建的MySQL数据库。
sudo mkdir -p /etc/postfix/sql
打开文本编辑器并创建以下文件:
/etc/postfix/sql/mysql_virtual_domains_maps.cf
user = postfixadmin
password = P4ssvv0rD
hosts = 127.0.0.1
dbname = postfixadmin
query = SELECT domain FROM domain WHERE domain='%s' AND active = '1'
/etc/postfix/sql/mysql_virtual_alias_maps.cf
user = postfixadmin
password = P4ssvv0rD
hosts = 127.0.0.1
dbname = postfixadmin
query = SELECT goto FROM alias WHERE address='%s' AND active = '1'
/etc/postfix/sql/mysql_virtual_alias_domain_maps.cf
user = postfixadmin
password = P4ssvv0rD
hosts = 127.0.0.1
dbname = postfixadmin
query = SELECT goto FROM alias,alias_domain WHERE alias_domain.alias_domain = '%d' and alias.address = CONCAT('%u', '@', alias_domain.target_domain) AND alias.active = 1 AND alias_domain.active='1'
/etc/postfix/sql/mysql_virtual_alias_domain_catchall_maps.cf
user = postfixadmin
password = P4ssvv0rD
hosts = 127.0.0.1
dbname = postfixadmin
query = SELECT goto FROM alias,alias_domain WHERE alias_domain.alias_domain = '%d' and alias.address = CONCAT('@', alias_domain.target_domain) AND alias.active = 1 AND alias_domain.active='1'
/etc/postfix/sql/mysql_virtual_mailbox_maps.cf
user = postfixadmin
password = P4ssvv0rD
hosts = 127.0.0.1
dbname = postfixadmin
query = SELECT maildir FROM mailbox WHERE username='%s' AND active = '1'
/etc/postfix/sql/mysql_virtual_alias_domain_mailbox_maps.cf
user = postfixadmin
password = P4ssvv0rD
hosts = 127.0.0.1
dbname = postfixadmin
query = SELECT maildir FROM mailbox,alias_domain WHERE alias_domain.alias_domain = '%d' and mailbox.username = CONCAT('%u', '@', alias_domain.target_domain) AND mailbox.active = 1 AND alias_domain.active='1'
创建SQL配置文件后,更新主Postfix配置文件以包含有关存储在MySQL数据库中的虚拟域,用户和别名的信息。
sudo postconf -e "virtual_mailbox_domains = mysql:/etc/postfix/sql/mysql_virtual_domains_maps.cf"sudo postconf -e "virtual_alias_maps = mysql:/etc/postfix/sql/mysql_virtual_alias_maps.cf, mysql:/etc/postfix/sql/mysql_virtual_alias_domain_maps.cf, mysql:/etc/postfix/sql/mysql_virtual_alias_domain_catchall_maps.cf"sudo postconf -e "virtual_mailbox_maps = mysql:/etc/postfix/sql/mysql_virtual_mailbox_maps.cf, mysql:/etc/postfix/sql/mysql_virtual_alias_domain_mailbox_maps.cf"
postconf命令显示配置参数的实际值,更改配置参数值或显示有关Postfix邮件系统的其他配置信息。
本地交付代理会将传入的电子邮件传递到用户的邮箱。运行以下命令将Dovecot的LMTP服务设置为默认邮件传输服务:
sudo postconf -e "virtual_transport = lmtp:unix:private/dovecot-lmtp"
使用先前生成的Let的加密SSL证书设置TL参数:
sudo postconf -e 'smtp_tls_security_level = may'sudo postconf -e 'smtpd_tls_security_level = may'sudo postconf -e 'smtp_tls_note_starttls_offer = yes'sudo postconf -e 'smtpd_tls_loglevel = 1'sudo postconf -e 'smtpd_tls_received_header = yes'sudo postconf -e 'smtpd_tls_cert_file = /etc/letsencrypt/live/mail.myfreax.com/fullchain.pem'sudo postconf -e 'smtpd_tls_key_file = /etc/letsencrypt/live/mail.myfreax.com/privkey.pem'
配置经过身份验证的SMTP设置并将身份验证移交给Dovecot:
sudo postconf -e 'smtpd_sasl_type = dovecot'sudo postconf -e 'smtpd_sasl_path = private/auth'sudo postconf -e 'smtpd_sasl_local_domain ='sudo postconf -e 'smtpd_sasl_security_options = noanonymous'sudo postconf -e 'broken_sasl_auth_clients = yes'sudo postconf -e 'smtpd_sasl_auth_enable = yes'sudo postconf -e 'smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination'
我们还需要编辑Postfix主配置文件master.cf
并启用提交端口(587
)和smtps端口(465
)。
使用文本编辑器打开文件并取消注释/编辑以下行:
/etc/postfix/master.cf
submission inet n - y - - smtpd
-o syslog_name=postfix/submission
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
# -o smtpd_reject_unlisted_recipient=no
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
# -o smtpd_helo_restrictions=$mua_helo_restrictions
# -o smtpd_sender_restrictions=$mua_sender_restrictions
# -o smtpd_recipient_restrictions=
# -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
smtps inet n - y - - smtpd
-o syslog_name=postfix/smtps
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
# -o smtpd_reject_unlisted_recipient=no
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
# -o smtpd_helo_restrictions=$mua_helo_restrictions
# -o smtpd_sender_restrictions=$mua_sender_restrictions
# -o smtpd_recipient_restrictions=
# -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
重新启动Postfix服务以使更改生效。
sudo systemctl restart postfix
此时您已成功配置Postfix服务。
配置Dovecot
在本节中,我们将配置Dovecot以匹配我们的设置
首先配置dovecot-sql.conf.ext
指示Dovecot如何访问数据库的文件以及如何查找有关电子邮件帐户的信息。
/etc/dovecot/dovecot-sql.conf.ext
driver = mysql
connect = host=127.0.0.1 dbname=postfixadmin user=postfixadmin password=P4ssvv0rD
default_pass_scheme = MD5-CRYPT
iterate_query = SELECT username AS user FROM mailbox
user_query = SELECT CONCAT('/var/mail/vmail/',maildir) AS home, \
CONCAT('maildir:/var/mail/vmail/',maildir) AS mail, \
5000 AS uid, 5000 AS gid, CONCAT('*:bytes=',quota) AS quota_rule \
FROM mailbox WHERE username = '%u' AND active = 1
password_query = SELECT username AS user,password FROM mailbox \
WHERE username = '%u' AND active='1'
不要忘记使用正确的MySQL凭据(数据库,用户和密码)。
接下来,编辑conf.d/10-mail.conf
文件并编辑以下变量:
/etc/dovecot/conf.d/10-mail.conf
...
mail_location = maildir:/var/mail/vmail/%d/%n
...
mail_uid = vmail
mail_gid = vmail
...
first_valid_uid = 5000
last_valid_uid = 5000
...
mail_privileged_group = vmail
...
mail_plugins = quota
...
要使身份验证工作,请打开conf.d/10-auth.conf
,编辑以下行并包含该auth-sql.conf.ext
文件:
/etc/dovecot/conf.d/10-auth.conf
...
disable_plaintext_auth = yes
...
auth_mechanisms = plain login
...
#!include auth-system.conf.ext
!include auth-sql.conf.ext
...
打开conf.d/10-master.conf
文件,并按如下所示进行修改:
/etc/dovecot/conf.d/10-master.conf
...
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
mode = 0600
user = postfix
group = postfix
}
...
}
...
service auth {
...
unix_listener auth-userdb {
mode = 0600
user = vmail
group = vmail
}
...
unix_listener /var/spool/postfix/private/auth {
mode = 0666
user = postfix
group = postfix
}
...
}
...
service auth-worker {
user = vmail
}
...
service dict {
unix_listener dict {
mode = 0660
user = vmail
group = vmail
}
}
...
打开conf.d/10-ssl.conf
并启用SSL / TLS。
/etc/dovecot/conf.d/10-ssl.conf
...
ssl = yes
...
ssl_cert = </etc/letsencrypt/live/mail.myfreax.com/fullchain.pem
ssl_key = </etc/letsencrypt/live/mail.myfreax.com/privkey.pem
ssl_dh = </etc/ssl/certs/dhparam.pem
...
ssl_cipher_list = EECDH+AES:EDH+AES+aRSA
...
ssl_prefer_server_ciphers = yes
...
确保使用SSL证书文件的正确路径。
如果你之前已经配置过PostFix,你应该已经有fullchain.pem
,privkey.pem
,dhparam.pem
文件在您的服务器上。有关如何创建免费的Let't Encrypt SSL证书和Diffie-Hellman密钥的更多信息,请查看本教程
打开conf.d/20-imap.conf
文件并激活imap_quota
插件:
/etc/dovecot/conf.d/20-imap.conf
...
protocol imap {
...
mail_plugins = $mail_plugins imap_quota
...
}
...
打开conf.d/20-lmtp.conf
文件并按如下所示进行编辑:
/etc/dovecot/conf.d/20-lmtp.conf
...
protocol lmtp {
postmaster_address = postmaster@myfreax.com
mail_plugins = $mail_plugins
}
...
在conf.d/20-lmtp.conf
文件中定义默认邮箱:
/etc/dovecot/conf.d/15-mailboxes.conf
...
mailbox Drafts {
special_use = \Drafts
}
mailbox Spam {
special_use = \Junk
auto = subscribe
}
mailbox Junk {
special_use = \Junk
}
...
有两种不同类型的配额大小,一种是针对整个域设置的,另一种是针对每个用户邮箱设置的。在本系列的前一部分中,我们已经在PostfixAdmin中启用了配额支持,这意味着配额信息将存储在PostfixAdmin数据库中
现在,我们需要配置Dovecot以连接到数据库,处理配额限制以及运行脚本,当用户的配额超过指定限制时,该脚本会向用户发送邮件。为此,请打开conf.d/90-quota.conf
文件并按如下所示进行修改:
/etc/dovecot/conf.d/90-quota.conf
plugin {
quota = dict:User quota::proxy::sqlquota
quota_rule = *:storage=5GB
quota_rule2 = Trash:storage=+100M
quota_grace = 10%%
quota_exceeded_message = Quota exceeded, please contact your system administrator.
quota_warning = storage=100%% quota-warning 100 %u
quota_warning2 = storage=95%% quota-warning 95 %u
quota_warning3 = storage=90%% quota-warning 90 %u
quota_warning4 = storage=85%% quota-warning 85 %u
}
service quota-warning {
executable = script /usr/local/bin/quota-warning.sh
user = vmail
unix_listener quota-warning {
group = vmail
mode = 0660
user = vmail
}
}
dict {
sqlquota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext
}
我们还需要告诉dovecot如何访问SQL配额字典。打开dovecot-dict-sql.conf.ext
文件并编辑以下行:
/etc/dovecot/dovecot-dict-sql.conf.ext
...
connect = host=127.0.0.1 dbname=postfixadmin user=postfixadmin password=P4ssvv0rD
...
map {
pattern = priv/quota/storage
table = quota2
username_field = username
value_field = bytes
}
map {
pattern = priv/quota/messages
table = quota2
username_field = username
value_field = messages
}
...
# map {
# pattern = shared/expire/$user/$mailbox
# table = expires
# value_field = expire_stamp
#
# fields {
# username = $user
# mailbox = $mailbox
# }
# }
...
确保使用正确的MySQL凭据(数据库,用户和密码)。
创建以下shell脚本,如果其配额超出指定限制,将向用户发送电子邮件:
/usr/local/bin/quota-warning.sh
#!/bin/sh
PERCENT=$1
USER=$2
cat << EOF | /usr/lib/dovecot/dovecot-lda -d $USER -o "plugin/quota=dict:User quota::noenforcing:proxy::sqlquota"
From: postmaster@myfreax.com
Subject: Quota warning
Your mailbox is now $PERCENT% full.
EOF
通过运行以下命令使脚本可执行:
sudo chmod +x /usr/local/bin/quota-warning.sh
最后重启dovecot服务以使更改生效。
sudo systemctl dovecot restart
至此,您应该拥有功能齐全的邮件系统,在下一篇文章中我们将会配置并集成Rspamd邮件过滤器,如果你喜欢我们的内容可以选择在下方二维码中捐赠我们,或者点击广告予以支持,感谢你的支持