Ubuntu 18.04配置邮箱服务器(局域网)

-------------------------------------------Ubuntu 18.04配置邮箱服务器(局域网)-------------------------------------------
一、安装
　　Ubuntu 18.04附带了systemd-resolve，需要禁用它，因为它绑定到53端口，与Dnsmasq端口冲突。
  运行以下命令以禁用已解析的服务：

:$ systemctl disable systemd-resolved
:$ systemctl stop systemd-resolved

  删除符号链接resolv.conf文件

:$ ls -lh /etc/resolv.conf

  53端口占用：

:$ lsof -i:53
:$ kill -9 pid

  安装：

:$ apt-get install dovecot-common dovecot-imapd dovecot-pop3d
:$ apt-get install postfix
:$ apt-get install dnsmasq

  对应服务:
  Postfix------Smtp（发送邮件）
  Dovecot------POP3/IMAP（接收邮件）
  Dnsmasq------nameserver（域名服务器）

二、配置hostname

:$ vim /etc/hostname

  更改为:
  mail.coodyz.com
  重启后生效:

:$ reboot

三、配置dnsmasq
　在hosts文件中增加 本地IP到域名映射

:$ vim /etc/hosts192.168.254.128 mail.coodyz.com # `192.168.254.128`更改为Ubuntu本机局域网IP

　启动服务：

:$ /etc/init.d/dnsmasq start

  将服务器的DNS服务器指向Dnsmasq服务器：

:$ vim /etc/resolv.conf
nameserver 127.0.0.1
nameserver 8.8.8.8

  以上只是修改运行时文件，进行持久配置需编辑/etc/network/interfaces。

  测试：

:$ dig A mail.coodyz.com
; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> A mail.coodyz.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 47993
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;mail.coodyz.com.    IN    A

;; ANSWER SECTION:
mail.coodyz.com.    0    IN    A    192.168.254.128

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Dec 20 16:42:17 CST 2019
;; MSG SIZE rcvd: 60

四、配置postfix

:$ vim /etc/postfix/main.cf

  参考配置：

home_mailbox = Maildir/

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA‘s job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
compatibility_level = 2

# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = mail.coodyz.com
mydomain = coodyz.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = $mydomain
mydestination = $myhostname, coodyz.com, mail.coodyz.com, localhost.coodyz.com, localhost
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = ipv4

smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks, reject_unauth_destination
broken_sasl_auth_clients = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth

  启动服务:

:$ /etc/init.d/postfix start

五、配置dovecot
  编辑Dovecot主配置文件：

:# vim /etc/dovecot/dovecot.conf

  取消注释并配置

listen = *
protocols = pop3 imap
pop3_uidl_format = %08Xu%08Xv
mail_location = mbox:~/mail:INBOX=/var/mail/%u
disable_plaintext_auth = no

  指定电子邮件客户端向Dovecot进行身份验证的方式:

:# vim /etc/dovecot/conf.d/10-auth.conf
auth_mechanisms = plain login

  指定用于存储电子邮件的文件夹:

:# vim /etc/dovecot/conf.d/10-mail.conf
mail_location = maildir:/home/%u/Maildir

  编辑Postfix SMTP身份验证配置文件：

:$ vim /etc/dovecot/conf.d/10-master.conf

  注释文件中的以下几行

#unix_listener auth-userdb {
#mode = 0600
#user =
#group =
#}

  并确保未注释以下内容：

# Postfix smtp-auth
unix_listener /var/spool/postfix/private/auth {
mode = 0666
user = postfix
group = postfix
}

  编辑POP3配置文件，并允许一些较旧的电子邮件客户端正确连接和传输：:

:$ vim /etc/dovecot/conf.d/20-pop3.conf
pop3_uidl_format = %08Xu%08Xv
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh

  为了使Dovecot服务与Postfix服务一起使用，我们需要在Postfix配置文件中添加以下几行：

:$ vim /etc/postfix/main.cf
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks, reject_unauth_destination
broken_sasl_auth_clients = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth

  重启服务:

:$ /etc/init.d/postfix restart
:$ /etc/init.d/dovecot restart

  测试服务功能:

:$ telnet localhost 143
Trying 127.0.0.1...
Connected to localhost.
Escape character is ‘^]‘.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS 
AUTH=PLAIN AUTH=LOGIN] Dovecot (Ubuntu) ready.
:$ telnet localhost 110

  服务器启动时自启：

:$ update-rc.d dovecot defaults

  建立邮箱账户:

:$ adduser ted
Enter new UNIX password: ted
Retype new UNIX password: ted
passwd: password updated successfully
Changing the user information for test
Enter the new value, or press ENTER for the default
Full Name []: 
Room Number []: 
Work Phone []: 
Home Phone []: 
Other []: 
Is the information correct? [Y/n] Y

  重启服务：

:$ /etc/init.d/dovecot restart

六、使用测试
　注意：请确保两者在同一网段
　邮件服务器IP 192.168.254.128
　Windows XP 客户端IP 192.168.254.130

　使用outlook测试：
　工具->账户->添加

在Ubuntu端查看：

:~$ cd ~/Maildir/new/
:~/Maildir/new$ ls
1576825940.V801I10053cM500622.mail.coodyz.com
1576826245.V801I100544M69814.mail.coodyz.com
1576826459.V801I10054bM4159.mail.coodyz.com
1576833962.V801I10055bM300307.mail.coodyz.com
:~/Maildir/new$ vim 1576833962.V801I10055bM300307.mail.coodyz.com

参考链接：https://www.linuxidc.com/Linux/2017-03/141392.htm

　　　https://computingforgeeks.com/install-and-configure-dnsmasq-on-ubuntu-18-04-lts/

　　　https://kyup.com/tutorials/install-dovecot/

　　　https://tecadmin.net/install-dovecot-on-ubuntu/