1.环境初始化

[[email protected] ~]# rpm -q centos-release //查看系统版本
centos-release-7-5.1804.el7.centos.x86_64

[[email protected] ~]# vi /etc/hostname //将主机名更改为邮件服务器域名mail.test.com

[[email protected] ~]# systemctl disable firewalld //禁止防火墙开机自启动

[[email protected] ~]# vi /etc/sysconfig/selinux //将未注释的SELINUX行的值改为disabled

[[email protected] ~]# vi /etc/fstab //编辑fstab配置文件，在最后一行添加如下：

/dev/cdrom /mnt iso9660 ro 0 0 //将vmware连接的光盘镜像开机自动以只读挂载到/mnt目录下

[[email protected] ~]# vi /etc/yum.repos.d/CentOS-Base.repo //编辑yum的配置文件，方便后续安装，配置内容如下，其他删除或注释：

[base]
name=CentOS-$releasever - Base
baseurl=file:///mnt
enabled=1
gpgcheck=0
////////////没看懂什么意思，为什么要这样做
[[email protected] ~]# reboot //重启让优化环境生效

2.搭建DNS环境域名解析，用于解析postfix地址

[[email protected] ~]# yum install -y bind //安装DNS服务器

[[email protected] ~]# vi /etc/named.conf //修改DNS主配置文件

listen-on port 53 { 192.168.49.129; };

allow-query { any; }; //修改这两行的内容

[[email protected] ~]# vi /etc/named.rfc1912.zones //修改子配置文件

zone “test.com” IN {

type master;

    file "test.com.zone";

};

zone “49.168.192.in-addr.arpa” {

type master;

    file "test.com.local";

}; //在最后添加一个正向和一个反向解析区域

[[email protected] ~]# cd /var/named/ //进入DNS服务器区域配置文件目录

[[email protected] named]# cp -p named.localhost test.com.zone

[[email protected] named]# cp -p named.localhost test.com.local //复制模板区域配置文件为指定区域配置文件。保留源文件权限，确定属组为named

[[email protected] named]# vi test.com.zone //编辑正向区域配置文件
$TTL 1D
@ IN SOA @ rname.invalid. (

0       ; serial
                                    1D      ; refresh
                                    1H      ; retry
                                    1W      ; expire
                                    3H )    ; minimum
    NS      @
    A       192.168.49.129
    mail      A       192.168.49.129
    MX 10   mail.test.com.

[[email protected] named]# vi test.com.local //编辑反向区域配置文件
$TTL 1D
@ IN SOA test.com. rname.invalid. (

0       ; serial
                                    1D      ; refresh
                                    1H      ; retry
                                    1W      ; expire
                                    3H )    ; minimum
    NS      mail.test.com.
    A       192.168.49.129
    MX 10   mail.test.com.
    129     PTR     mail.test.com.

[[email protected] named]# systemctl start named //启动DNS域名解析服务器

[[email protected] named]# yum install -y bind-utils //安装nslookup命令测试dns能否解析成功

[[email protected] named]# vi /etc/resolv.conf //给本机的DNS指向自己的DNS服务器

nameserver 192.168.49.129

[[email protected] named]# nslookup mail.test.com //解析服务器地址 //正向解析
Server: 192.168.49.129
Address: 192.168.49.129#53

Name: mail.test.com
Address: 192.168.49.129

//反向解析
[[email protected] named]# nslookup 192.168.49.129
Server: 192.168.49.129
Address: 192.168.49.129#53

129.49.168.192.in-addr.arpa name = mail.test.com.
//成功

3.安装postfix服务器并进行配置

一般是默认自动安装postfix服务器的。

[[email protected] named]# rpm -q postfix //检查系统是否已经安装了postfix服务器

postfix-2.10.1-6.el7.x86_64

[[email protected] named]# postconf -a //检查postfix是否支持cyrus dovecot功能，如果不支持需重新安装更新的版本

[[email protected] named]# vi /etc/postfix/main.cf //编辑postfix的配置文件，查找并修改对应配置项

myhostname = mail.test.com //本机主机名

mydomain = test.com //服务器域名

myorigin = $mydomain //初始域名

inet_interfaces = 192.168.80.181,127.0.0.1 //监听接口

inet_protocols = ipv4 //监听网络版本，可以不改

mydestination = myhostname,

mydomain //目标域

home_mailBox = Maildir/ //邮件目录，在用户家目录下

[[email protected] named]# postfix check //检查配置文件是否有语法错误

[[email protected] named]# systemctl start postfix //启动postfix服务器

//postconf -n该命令可查看postfix非默认配置

• 1

4.邮件服务器简单发信测试

[[email protected] named]# groupadd mailusers //添加邮件账号组

[[email protected] named]# useradd -g mailusers -s /sbin/nologin jack //用户jack不允许登录（通过mailusers可以连接）

[[email protected] named]# passwd jack

[[email protected] named]# useradd -g mailusers -s /sbin/nologin tom

[[email protected] named]# passwd tom //添加jack、tom邮件服务测试账号

[[email protected] named]# yum install -y telnet //安装远程登录插件，用于登录25端口测试

[[email protected] named]# telnet mail.test.com 25 //远程登录25端口，如报错连接不上，重启postfix

[[email protected] named]# ls /home/tom/Maildir/new/ //查看tom接收的邮件目录下的邮件

from：对方收到邮件时显示的发件人
smtp：指定第三方发邮件的smtp服务器地址
set smtp-auth-user：第三方发邮件的用户名
set smtp-auth-password：用户名对应的密码,有些邮箱填的是授权码
smtp-auth：SMTP的认证方式，默认是login，也可以改成CRAM-MD5或PLAIN方式

因为需要 163邮箱的 SSL 证书，所以我们还需要手动的获取163邮箱的证书保存到本地指定的目录里以备调用和验证，具体命令如下：

mkdir -p /root/.certs/
echo -n | openssl s_client -connect smtp.163.com:465 | sed -ne ‘/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p‘ > ~/.certs/163.crt
certutil -A -n "GeoTrust SSL CA" -t "C," -d ~/.certs -i ~/.certs/163.crt
certutil -A -n "GeoTrust Global CA" -t "C," -d ~/.certs -i ~/.certs/163.crt
certutil -L -d /root/.certs

为了防止出现前文所说的发送邮件警告提示，还需要进入邮箱 SSL 证书存放目录 /root/.certs 里执行如下命令：

cd /root/.certs/
certutil -A -n "GeoTrust SSL CA - G3" -t "Pu,Pu,Pu" -d ./ -i 163.crt

返回如下提示即可：
Notice: Trust flag u is set automatically if the private key is present.

systemctl start postfix #启动邮件服务

测试：
echo "test" | mail -s "ec" [email protected]

一、Postfix简介

• Postfix 是一种电子邮件服务器，它是由任职于IBM华生研究中心（T.J. Watson Research Center）的荷兰籍研究员Wietse Venema为了改良sendmail邮件服务器而产生的。最早在1990年代晚期出现，是一个开放源代码的软件。
• Postfix 官方网站：http://www.postfix.org/
• Postfix 下载地址：http://www.postfix.org/download.html

二、Postfix安装

• 安装Postfix以配置SMTP服务器

[1] 即使CentOS系统安装了[最小安装]，也会安装Postfix，但如果Postfix不安装，请先安装它，如下所示。

[root@linuxprobe ~]# yum -y install postfix

[2] 此示例显示配置SMTP-Auth以使用Dovecot的SASL函数。

[root@linuxprobe ~]# vi /etc/postfix/main.cf
# line 75: uncomment and specify hostname

myhostname = linuxprobe.srv.world
# line 83: uncomment and specify domain name

mydomain = srv.world
# line 99: uncomment

myorigin = $mydomain
# line 116: change

inet_interfaces = all
# line 164: add

mydestination = $myhostname,localhost.$mydomain,localhost,$mydomain
# line 264: uncomment and specify your local network

mynetworks = 127.0.0.0/8,10.0.0.0/24
# line 419: uncomment (use mailBoxdir)

home_mailBox = mailBox/
# line 574: add

smtpd_banner = $myhostname ESMTP
# add follows to the end

# limit an email size for 10M

message_size_limit = 10485760

# limit a mailBox for 1G

mailBox_size_limit = 1073741824
# for SMTP-Auth

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

[root@linuxprobe ~]# systemctl restart postfix
[root@linuxprobe ~]# systemctl enable postfix

[3]如果Firewalld正在运行，请允许SMTP服务。 SMTP使用25 / TCP。

[root@dlp ~]# firewall-cmd --add-service=smtp --permanent
success
[root@dlp ~]# firewall-cmd --reload
success

三、Dovecot 安装

• 安装Dovecot以配置POP / IMAP服务器

[1] 安装Dovecot.

[root@linuxprobe ~]# yum -y install dovecot

[2] 此示例显示配置为向Postfix提供SASL功能 .

[root@linuxprobe ~]# vi /etc/dovecot/dovecot.conf
# line 24: uncomment
protocols = imap pop3 lmtp
# line 30: uncomment and change ( if not use IPv6 )
listen = *
[root@linuxprobe ~]# vi /etc/dovecot/conf.d/10-auth.conf
# line 10: uncomment and change ( allow plain text auth )
disable_plaintext_auth = no
# line 100: add
auth_mechanisms = plain login
[root@linuxprobe ~]# vi /etc/dovecot/conf.d/10-mail.conf
# line 30: uncomment and add
mail_location = maildir:~/Maildir
[root@linuxprobe ~]# vi /etc/dovecot/conf.d/10-master.conf
# line 96-98: uncomment and add like follows
# Postfix smtp-auth
unix_listener /var/spool/postfix/private/auth {
    mode = 0666
    user = postfix
    group = postfix
}
[root@linuxprobe ~]# vi /etc/dovecot/conf.d/10-ssl.conf
# line 8: change (not require SSL)
ssl = no

[root@linuxprobe ~]# systemctl start dovecot
[root@linuxprobe ~]# systemctl enable dovecot

[3] 如果Firewalld正在运行，请允许POP / IMAP服务。 POP使用110 / TCP，IMAP使用143 / TCP.

[root@vdevops ~]# firewall-cmd --add-port={110/tcp,143/tcp} --permanent
success
[root@vdevops ~]# firewall-cmd --reload
success

四、SSL设置

• 配置SSL以加密连接

[1] 首先创建证书，传送门：http://www.jb51.cc/article/p-pukuckix-qq.html
[2] 为SSL配置Postfix和Dovecot。

# add to the end
smtpd_use_tls = yes
smtpd_tls_cert_file = /etc/pki/tls/certs/server.crt
smtpd_tls_key_file = /etc/pki/tls/certs/server.key
smtpd_tls_session_cache_database = btree:/etc/postfix/smtpd_scache
[root@linuxprobe ~]# vi /etc/postfix/master.cf
# line 26-28: uncomment
smtps       inet   n       -       n       -       -       smtpd
  -o syslog_name=postfix/smtps
  -o smtpd_tls_wrappermode=yes
[root@linuxprobe ~]# vi /etc/dovecot/conf.d/10-ssl.conf
# line 8: change
ssl = yes
# line 14,15: specify certificates
ssl_cert = </etc/pki/tls/certs/server.crt
ssl_key = </etc/pki/tls/certs/server.key
[root@linuxprobe ~]# systemctl restart postfix dovecot

[3] 如果Firewalld正在运行，请允许SMTPS / POP3S / IMAPS服务。 SMTPS使用465 /
TCP，POP3S使用995 / TCP，IMAPS使用993 / TCP。

[root@vdevops ~]# firewall-cmd --add-service={pop3s,imaps} --permanent
success
[root@vdevops ~]# firewall-cmd --add-port=465/tcp --permanent
success
[root@vdevops ~]# firewall-cmd --reload
success

邮件日志报告：pflogsumm

• 安装pflogsumm这是Postfix日志报告工具

[1] 安装postfix-perl-scripts包 .

[root@linuxprobe ~]# yum -y install postfix-perl-scripts
# generate log summary for yesterday
[root@linuxprobe ~]# perl /usr/sbin/pflogsumm -d yesterday /var/log/maillog
Postfix log summaries for Jul 14
Grand Totals ------------
messages
 2 received
 5 delivered
 0 forwarded
 0 deferred
 0 bounced
 0 rejected (0%)
 0 reject warnings
 0 held
 0 discarded (0%)

 2879 bytes received
 6572 bytes delivered
 1 senders
 1 sending hosts/domains
 2 recipients
 2 recipient hosts/domains
Per-Hour Traffic Summary ------------------------
 time received delivered deferred bounced rejected
 --------------------------------------------------------------------
 0000-0100 0 0 0 0 0
 0100-0200 0 0 0 0 0
 0200-0300 0 0 0 0 0
 0300-0400 0 0 0 0 0
 0400-0500 0 0 0 0 0
 0500-0600 0 0 0 0 0
 0600-0700 0 0 0 0 0
 0700-0800 0 0 0 0 0
 0800-0900 0 0 0 0 0
 0900-1000 0 0 0 0 0
 1000-1100 2 5 0 0 0
 1100-1200 0 0 0 0 0
 1200-1300 0 0 0 0 0
 1300-1400 0 0 0 0 0
 1400-1500 0 0 0 0 0
 1500-1600 0 0 0 0 0
 1600-1700 0 0 0 0 0
 1700-1800 0 0 0 0 0
 1800-1900 0 0 0 0 0
 1900-2000 0 0 0 0 0
 2000-2100 0 0 0 0 0
 2100-2200 0 0 0 0 0
 2200-2300 0 0 0 0 0
 2300-2400 0 0 0 0 0

Host/Domain Summary: Message Delivery --------------------------------------
 sent cnt bytes defers avg dly max dly host/domain
 -------- ------- ------- ------- ------- -----------
 3 4119 0 0.4 s 0.8 s srv.world
 2 2453 0 0.1 s 0.1 s mail.srv.world

Host/Domain Summary: Messages Received ---------------------------------------
 msg cnt bytes host/domain
 -------- ------- -----------
 2 2879 mail.srv.world

Senders by message count ------------------------
 2 cent@mail.srv.world

Recipients by message count ---------------------------
 3 redhat@srv.world
 2 cent@mail.srv.world

Senders by message size -----------------------
 2879 cent@mail.srv.world

Recipients by message size --------------------------
 4119 redhat@srv.world
 2453 cent@mail.srv.world

message deferral detail: none
message bounce detail (by relay): none
message reject detail: none
message reject warning detail: none
message hold detail: none
message discard detail: none
smtp delivery failures: none
Warnings --------
 tlsmgr (total: 6)
 3 redirecting the request to postfix-owned data_directory /var/li...
 3 request to update table btree:/etc/postfix/smtpd_scache in non-...

Fatal errors: none
Panics: none
Master daemon messages ----------------------
 4 daemon started -- version 2.10.1,configuration /etc/postfix
 3 terminating on signal 15
 1 reload -- version 2.10.1,configuration /etc/postfix

[root@linuxprobe ~]# crontab -e
# 发送邮件日志摘要在AM每天1:00到根
00 01 * * * perl /usr/sbin/pflogsumm -e -d yesterday /var/log/maillog | mail -s 'Logwatch for Postfix' root