一、基于电子邮件发送：
电子邮件发送
（1）服务器使用SMTP协议将电子邮件提交至TCP端口25,或由本地客户端通过/usr/bin/sendmail程序进行提交。如果该MTA是最终目标位置,邮件将传递至MDA。否则,将使用MX记录在DNS中查找下一个MTA,并使用SMTP进行转发。
（2）MDA:“邮件发送代理”。MDA将邮件发送至收件人的本地邮件存储位置(默认情况下是/var/spool/mail/user)。Postfix提供自己的MDA,以发送至基于文件的本地默认邮件存储位置/usr/libexec/postfix/local.
（3）转发:电子邮件服务器(MTA)将提交的邮件转发至另一个服务器,以进行发送
（4）排队:失败的发送或转发尝试排队等待,并由MTA定义重试。(默认情况下,Postfix每小时执行此操作一次
（5）拒绝:在首次提交期间,电子邮件被电子邮件服务器拒绝
（6）退回:远程服务器接受电子邮件以进行发送以后,又将该电子邮件退回给始发电子邮件服务器和/或用户
（7）电子邮件以进行发送以后,又将该电子邮件退回给始发电子邮件服务器和/或用户
Postfix由postfix RPM包提供,并通过postfix服务脚本控制。它是一个由多个协同操作程序构成的模块
化程序,它的组件由master进程控制。
Postfix的主配置文件是/etc/postfix/main.cf,可以使用文本编辑器或postconf命令进行编辑。postconf
命令还可用于确定Postfix的所有当前和默认配置设置或逐项确定这些设置。
默认情况下,Postfix仅侦听来自本地主机的传入电子邮件。若要重新配置postfix以接收从远程主机发
送的本地邮件,必须在/etc/postfix/main.cf中设置inet_interfaces = all
对电子邮件进行故障排除时,将在/var/log/maillog中保留所有与邮件相关的操作日志,其中包括关于
被事件和成功事件的信息。mailq命令(或postqueue -p)显示已排队的所有传出邮件的列表。若要尝试
再次立即发送所有已排队的邮件,可以运行postfix flush命令(或postqueue -f);否则,postfix将大
约每小时尝试重新发送一次,直至邮件被接受或过期。
实验环境：
服务器端server： willis.com 172.25.254.1
客户端desktop： desktop.com 172.25.254.2
实验内容： 1.邮件远程发送
2.邮件别名
3.邮件群发
4.空壳邮件服务搭建
5.不同服务器之间邮件传送（DNS邮件解析）
6.出栈地址伪装
7.客户端主机名/地址限制 :（通过IP限制发件)
8.通过发件人地址进行限制 :（通过地址限制发件）
9.通过收件人地址进行过滤 :（限制收件）
1.邮件远程发送 1.1服务端
1.1-1 systemctl stop firewalld
yum install postfix
1.1-2vim /etc/postfix/main.cf
mydomain = willis.com #收件方看到的方邮件方主机名
myorigin = $mydomain
inet_interfaces = all #开启接口
#inet_interfaces = localhost #关闭只允许本地访问
mydestination = $myhostname, $mydomain, localhost #
1.1-3.systemctl restart postfix
netstat antlpe |grep master #查看端口
[root@willis ~]# netstat -antple |grep master
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 0 43632 2497/master
tcp6 0 0 :::25 :::* LISTEN 0 43633 2497/master
1.2.远程发送端(客户端)
[root@desktop ~]# yum install telnet -y
[root@desktop ~]# telnet 172.25.254.1 25 Trying 172.25.254.1... Connected to 172.25.254.1. Escape character is '^]'. 220 linux.com ESMTP Postfixehlo hello250-linux.com 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN
2.邮件别名
2.1.vim /etc/aliases
最后添加 admin: root ###给root一个别名为admin
2.2.postalias /etc/aliases ###重读别名文件
2.3.systemctl restart postfix
2.4.id admin ###可查看到admin用户不存在
mail admin ###相当于给root用户发送邮件
mail ###查看root用户的邮件
[root@willis ~]# vim /etc/aliases
[root@willis ~]# postalias /etc/aliases
[root@willis ~]# systemctl restart postfix.service
[root@willis ~]# id willis
id: willis: no such user
[root@willis ~]# mail willis
Subject: hello
hello , my name is willis,how are you.
.
EOT
[root@willis ~]# mail
Heirloom Mail version 12.5 7/5/10. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root Fri Sep 9 10:36 18/567 "hello"
& 1
Message 1:
From [email protected] Fri Sep 9 10:36:54 2016
Return-Path: <[email protected]>
X-Original-To: willis
Delivered-To: [email protected]
Date: Fri, 09 Sep 2016 10:36:54 +0800
To: [email protected]
Subject: hello
User-Agent: Heirloom mailx 12.5 7/5/10
Content-Type: text/plain; charset=us-ascii
From: [email protected] (root)
Status: R
hello , my name is willis,how are you.
& q
Held 1 message in /var/spool/mail/root
3.邮件群发
1.vim /etc/postfix/moreuser
root
student
2.vim /etc/aliases
最后添加 more: :include:/etc/postfix/moreuser
3.postalias /etc/aliases
4.systemctl restart postfix
5.mail more ###群发邮件
mail ###查看root用户的邮件
mail -u student ###查看student用户的邮件
[root@willis ~]# >/var/spool/mail/root
[root@willis ~]# useradd student
[root@willis ~]# vim /etc/postfix/moreuser
root
student
[root@willis ~]# vim /etc/aliases
[root@willis ~]# postalias /etc/aliases
[root@willis ~]# systemctl restart postfix.service
[root@willis ~]# mail more
Subject: hello-world
hello world.
.
EOT
[root@willis ~]# mail
Heirloom Mail version 12.5 7/5/10. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root Fri Sep 9 10:42 21/661 "hello-world"
& q
Held 1 message in /var/spool/mail/root
[root@willis ~]# mail -u student
Heirloom Mail version 12.5 7/5/10. Type ? for help.
"/var/mail/student": 1 message 1 new
>N 1 root Fri Sep 9 10:42 21/664 "hello-world"
& q
Held 1 message in /var/mail/student
4.空壳邮件服务搭建
4.1.在desktop（另外一台仅中转邮件的服务器,空壳端）上
postconf -e "inet_interfaces = all"
postconf -e "mydomain = willis.com"
postconf -e 'myorigin = $mydomain'
postconf -e "mydestination = "
postconf -e "relayhost = 172.25.254.1"
postconf -e "local_transport = error:local delivery disabled "
systemctl restart postfix.service （附注：火墙要关闭systemctl stop firewalld selinux要置0 setenforce 0 ）
[root@desktop ~]# postconf -e "mydomain = willis.com"
[root@desktop ~]# postconf -e 'myorigin = $mydomain'
[root@desktop ~]# postconf -e "mydestination = "
[root@desktop ~]# postconf -e "relayhost = 172.25.254.1"
[root@desktop ~]# postconf -e "local_transport = error:local delivery disabled "
[root@desktop ~]# systemctl restart postfix.service 4.2.在主服务器server上
postconf -e "mynetworks = 127.0.0.0/8 172.25.254.0/24"
#接受来自那个网段的邮件
systemctl restart postfix.service （附注：火墙要关闭systemctl stop firewalld selinux要置0 setenforce 0 ）
[root@willis ~]# postconf -e "mynetworks = 127.0.0.0/8 172.25.254.0/24"
You have mail in /var/spool/mail/root
[root@willis ~]# systemctl restart postfix.service
4.3.实验验证 在desktop（另外一台仅中转邮件的服务器）上（> /var/log/maillog ###清空邮件日志） mail root ###发送文件[root@desktop ~]# >/var/log/maillog
[root@desktop ~]# mail root
Subject: beautiful world
Threr are many beautiful things.
.
EOT
[root@desktop ~]# mail
No mail for root
在主服务器server上（ > /var/spool/mail/root ###清空邮件） mail ###查看文件 [root@willis ~]# >/var/spool/mail/root
[root@willis ~]# mail
Heirloom Mail version 12.5 7/5/10. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root Fri Sep 9 10:54 21/756 "beautiful world"
& q
Held 1 message in /var/spool/mail/root
5.不同服务器之间的邮件传送(DNS邮件解析记录) 将前面做实验的环境恢复到初始状态。
vim /etc/postfix/main.cf
mydomain = willis.com
myorigin = $mydomain
inet_interfaces = all
#inet_interfaces = localhost
mydestination = $myhostname, $mydomain, localhost
5-1server端配置dns
hostnamectl set-hostname mail.willis.com
安装DNS：yum install bind -y
1)vim /etc/resolv.conf
search willis.com
nameserver 172.25.254.12)vim /etc/named.rfc1912.zoneszone "willis.com" IN {
type master;
file "willis.com.zone";
allow-update { none; };
};
zone "redhat.com" IN {
type master;
file "redhat.com.zone";
allow-update { none; };
};3)cd /var/named/
cp -p named.localhost willis.com.zone4)vim willis.com.zone$TTL 1D
@ IN SOA dns.willis.com. root. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
NS dns.willis.com.
dns A 172.25.254.1
willis.com. MX 1 172.25.254.1.5)cp -p willis.com.zone redhat.com.zone
vim redhat.com.zone$TTL 1D
@ IN SOA dns.redhat.com. root. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
NS dns.redhat.com.
dns A 172.25.254.1
redhat MX 1 172.25.254.2. 6)systemctl start named 5-2 . desktop端配置
hostnamectl set-hostname mail.redhat.com
1)vim /etc/resolv.conf
search redhat.com
nameserver 172.25.254.1
2)测试
mail [email protected]
mail [email protected] [root@mail ~]# mail [email protected]
Subject: hello-willis
hello . you are a good boy.
.
EOT
[root@mail ~]# mail [email protected]
Subject: hello goog boy
Are you ok now?
.
EOT
You have new mail in /var/spool/mail/root
[root@mail ~]# mail
[root@mail ~]# mail [email protected]
Subject: hello good boy.
Are you OK now?
.
EOT
[root@mail ~]# mail
Heirloom Mail version 12.5 7/5/10. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root Fri Sep 9 12:24 18/569 "hello good boy."
& 1
Message 1:
From [email protected] Fri Sep 9 12:24:07 2016
Return-Path: <[email protected]>
X-Original-To: [email protected]
Delivered-To: [email protected]
Date: Fri, 09 Sep 2016 12:24:07 +0800
To: [email protected]
Subject: hello good boy.
User-Agent: Heirloom mailx 12.5 7/5/10
Content-Type: text/plain; charset=us-ascii
From: [email protected] (root)
Status: R
Are you OK now?
6.出栈地址伪装 6.1服务器端（伪装端）
vim /etc/postfix/generic 增加 [email protected] [email protected] postmap generic ###生成generic.db文件 postconf -d | grep generic postconf -e "smtp_generic_maps = hash:/etc/postfix/generic" systemctl restart postfix.service
测试 mail [email protected]
[root@willis postfix]# mail [email protected]
Subject: hello.
你好呀
.
EOT
6.2 接受端
[root@mail ~]# mail
Heirloom Mail version 12.5 7/5/10. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root Fri Sep 9 12:47 21/733 "hello."
& 1
Message 1:
From [email protected] Fri Sep 9 12:47:10 2016
Return-Path: <[email protected]>
X-Original-To: [email protected]
Delivered-To: [email protected]
Date: Fri, 09 Sep 2016 12:47:11 +0800
To: [email protected]
Subject: hello.
User-Agent: Heirloom mailx 12.5 7/5/10
Content-Type: text/plain; charset=utf-8
From: [email protected] (root)
Status: R
你好呀
7.客户端主机名/地址限制 :（通过IP限制发件)
postconf -e "smtpd_client_restrictions
= check_client_access hash:/etc/postfix/access"
vim /etc/postfox/main.cf
smtpd_client_restrictions = check_client_access hash:/etc/postfix/access,
vim /etc/postfox/access
192.168.0.4 REJECT
192.168.0 REJECT
postmap access
systemctl restart postfix 8.通过发件人地址进行限制 :（通过地址限制发件）
postconf -e "smtpd_sender_restrictions
= check_sender_access hash:/etc/postfix/sender"
vim /etc/postfox/main.cf
smtpd_sender_restrictions =
check_sender_access hash:/etc/postfix/sender
vim /etc/postfix/sender
[email protected] REJECT(OK、RELAY)
postmap sender
systemctl restart postfix9.通过收件人地址进行过滤 :（限制收件）
postconf -e "smtpd_recipient_restrictions = check_recipient_access hash:/etc/postfix/recipient"
vim /etc/postfox/main.cf smtpd_recipient_restrictions = check_recipient_access hash:/etc/postfix/recipient
vim /etc/postfix/recipient [email protected] REJECT(OK、RELAY,DISCARDED)
postmap recipient