Postfix比作邮局, Dovecot就是邮局管家.提供用户合法认证, 对外提供POP, IMAP 服务.这样常用的电邮客户端就能连入邮局,收发和管理信件.电邮相关软件,一律放在/opt/tsMail文件夹下,方便布署,还能尽可能不污染当前的操作系统环境.我们用的Dovecot 2.3.17,来自官网 https://www.dovecot.org/ 源码下载,编译而成,以保证目前(2022.01.05)具最新功能.

1. 新建用户和组

sudo groupadd -g 5000 vmail
sudo useradd -g vmail -u 5000 vmail -d /opt/tsMail/var/mail

groupadd -g 1012 dovecot &&
useradd -c "Dovecot unprivileged user" -d /dev/null -u 1012 \
        -g dovecot -s /bin/false dovecot &&
groupadd -g 1013 dovenull &&
useradd -c "Dovecot login user" -d /dev/null -u 1013 \
        -g dovenull -s /bin/false dovenull

2. 文件目录及权限

sudo mkdir -p /opt/tsMail/var/mail/vhosts/otherhill.com
sudo chown -R vmail:vmail /opt/tsMail/var/mail
sudo chown -R vmail:dovecot /opt/tsMail/etc/dovecot
chmod -R o-rwx /opt/tsMail/etc/dovecot

3. Dovecot 配置文件

a).  /opt/tsMail/etc/dovecot/dovecot.conf

listen = *,::

#submission
protocols = imap imaps pop3 pop3s  lmtp


log_path = /var/log/dovecot.log
log_timestamp = "%Y-%m-%d %H:%M:%S "


!include conf.d/*.conf
verbose_ssl = yes

b). /opt/tsMail/etc/dovecot/conf.d/10-auth.conf

auth_debug = yes
auth_debug_passwords = yes

#cram-md5
auth_mechanisms = plain login
disable_plaintext_auth = yes

auth_verbose = yes
ssl = yes

!include auth-sql.conf.ext

c). /opt/tsMail/etc/dovecot/conf.d/auth-sql.conf.ext

passdb {
  driver = sql
  args = /opt/tsMail/etc/dovecot/dovecot-sql.conf.ext
}

userdb {
  driver = static
  args = uid=vmail gid=vmail home=/opt/tsMail/var/mail/vhosts/%d/%n
}

d). /opt/tsMail/etc/dovecot/dovecot-sql.conf.ext

#https://www.linode.com/docs/guides/email-with-postfix-dovecot-and-mysql/
driver = mysql

connect = host=127.0.0.1 dbname=ts_mail user=root password=your_mysql_password
default_pass_scheme = SHA512-CRYPT
password_query = SELECT email as user, password FROM virtual_users WHERE email='%u';

e). /opt/tsMail/etc/dovecot/conf.d/10-mail.conf

mail_location = maildir:/opt/tsMail/var/mail/vhosts/%d/%n/

mail_privileged_group = mail
mail_plugins = $mail_plugins quota

f). /opt/tsMail/etc/dovecot/conf.d/10-master.conf

service imap-login {
   inet_listener imap {
     #port = 143
     port = 4147
   }

  inet_listener imaps {
    #port = 993
    port = 4150
    ssl = yes
  }
}

service pop3-login {
   inet_listener pop3 {
    #port = 110
    port = 4146
  }

  inet_listener pop3s {
    #port = 995
    port = 4151
    ssl = yes
  }
}


service lmtp {
  unix_listener  /opt/tsMail/var/spool/postfix/private/dovecot-lmtp {
   mode = 0666
   user = postfix
   group = postfix

  }
}

service quota-status {
    executable = quota-status -p postfix
    inet_listener {
        port = 12340
        # You can choose any port you want
    }
    client_limit = 1
}

service auth {
  unix_listener /opt/tsMail/var/spool/postfix/private/auth {
    mode = 0660
    user = postfix
    group = postfix
  }

  unix_listener auth-userdb {
    mode = 0600
    user = vmail
  }
  user = dovecot
}

service auth-worker {
  user = vmail
}

g). /opt/tsMail/etc/dovecot/conf.d/10-ssl.conf

ssl = required

ssl_cert = </opt/ssl/otherhill.com/fullchain.pem
ssl_key  = </opt/ssl/otherhill.com/privkey.pem

ssl_min_protocol = TLSv1.2
ssl_protocols = !SSLv3 !TLSv1 !TLSv1.1

ssl_cipher_list = TLS13-AES-128-GCM-SHA256:TLS13-CHACHA20-POLY1305-SHA256:TLS13-AES-256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-RSA-AES256-GCM-SHA384:AES128-SHA:AES256-SHA:RC4-SHA:DES-CBC3-SHA:RC4-MD5

h). /opt/tsMail/etc/dovecot/conf.d/20-imap.conf

protocol imap {
  # Space separated list of plugins to load (default is global mail_plugins).
  mail_plugins = $mail_plugins imap_quota
}

i). /opt/tsMail/etc/dovecot/conf.d/20-lmtp.conf

protocol lmtp {
  postmaster_address = postmaster@otherhill.com   # required
  hostname=mail.otherhill.com
}

j). /opt/tsMail/etc/dovecot/conf.d/90-quota.conf

plugin {
  quota = count:User quota
  quota_max_mail_size = 100M
  # Required for 'count' quota driver
  quota_vsizes = yes

  quota_rule = *:storage=1G
  quota_rule2 = Trash:storage=+100M

  # LDA/LMTP allows saving the last mail to bring user from under quota to
  # over quota, if the quota doesn't grow too high. Default is to allow as
  # long as quota will stay under 10% above the limit. Also allowed e.g. 10M.
  quota_grace = 10%%

  # Quota plugin can also limit the maximum accepted mail size.
  quota_max_mail_size = 100M
}

plugin {
    quota_status_success = DUNNO
    quota_status_nouser = DUNNO
    quota_status_overquota = "552 5.2.2 Mailbox is full"
}

设置用户邮箱容量为1G

4. Dovecot 常用命令行

a).查看当前配置
dovecot -c /opt/tsMail/etc/dovecot/dovecot.conf

b).显示指定帐户容量配额
doveadm quota get -u i@otherhill.com

c).启动,关闭与重载
dovecot -c /opt/tsMail/etc/dovecot/dovecot.conf
dovecot -c /opt/tsMail/etc/dovecot/dovecot.conf stop
dovecot -c /opt/tsMail/etc/dovecot/dovecot.conf reload

d).查看远程端口打开情况:
nmap mail.otherhill.com

e).查看本地端口打开情况:
netstat -tnla

f).查看dovecot打开端口情况:
[root@localhost postfix]# ss -lnpt | grep dovecot