Linux搭建Postfix邮件服务器

两台局域网计算机，分别有Win7/10系统和Vm虚拟机安装CentOs7系统
CentOs7的IP地址：192.168.81.133;192.168.81.134
Win7客户端(测试用),有Xshell或者SecureCRT工具

CentOs7下搭建Postfix邮件服务器，配置域名服务远程登录访问，新建用个测试用户(user1,user2)，两个用户用telnet命令登录邮件服务器，实现两个用户的邮件互发，并实现局域网内两个计算器的邮件互发

1.准备工作
2.搭建DNS服务   
3.搭建Postfix服务
4.Telnet的安装和配置
5.远程登录访并实现两个用户邮件互发
6.局域网内两台计算机邮件互发

systemctl stop firewalld
systemctl disable firewalld

setenforce 0

yum install bind -y

vim /etc/named.conf

vim /etc/named.rfc1912.zones

cp -p /var/named/named.localhost /var/named/duiyi.com.zone

vim /var/named/duiyi.com.zone

named-checkconf

systemctl start named
systemctl enable named

vim /etc/resolv.conf

nslookup mail.duiyi.com

rpm -q postfix

postconf -a

vim /etc/postfix/main.cf 

75行：myhostname = mail.duiyi.com //本机主机名

83行：mydomain = duiyi.com         //服务器域名

99行：myorigin = $mydomain         //初始域名

113行：inet_interfaces = 192.168.81.133,127.0.0.1 //监听接口

119行：inet_protocols = ipv4       //监听网络版本，可以不改

164行：mydestination = myhostname，mydomain    //目标域

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

postfix check

systemctl start postfix
systemctl enable postfix

useradd sentmsg
passwd sentmsg
useradd recvmsg
passwd recvmsg

ls /home

yum install telnet telnet -y
yum install telnet telnet-server -y

yum install xinetd -y

vim  /etc/xinetd.d/telnet

service telnet
{
   flags              = REUSE
   socket_type        = stream
   wait               = no
   user               = root
   server             = /usr/sbin/in.telnetd
   log_on_failure     += USERID 
   disable            = no      #将语句 disable = yes 改为 disable = no
}

systemctl restart xinetd

netstat -tnl | grep 23 

控制面板->程序->程序和功能->启动或关闭Windows功能->Telnet客户端  勾选并确定

telnet sentmsg@mail.duiyi.com

telnet recvmeg@mail.duiyi.com